feat: split nights off an accommodation booking as separate periods

addresses #869f6z36v

docs/api-consumer-guide.md

@@ -555,14 +555,16 @@ Single booking by UUID. `404 {"message":"Not found"}` if unknown.
   "totalDiscountLabel": null,
   "totalPrice": 123456,
   "pricingCurrency": "EUR",
-  "pricingVersion": 3,
+  "pricingVersion": 2,
   "priceBreakdown": {}
 }
 ```
 
 `totalPrice` and `totalDiscountAmount` are integer **minor units** (cents) — unlike the contingent endpoints. The three `*Discount` fields are whole **percentages** (1–100) or `null`, not amounts. `dateFrom`/`dateTo` are `Y-m-d`; `acceptedAt` is a full ISO-8601 datetime and is `null` until accepted. `priceBreakdown` is a computed nested structure.
 
-The first three discounts each apply to one section of the breakdown: `accommodationDiscount` to `basePrice + additionalPersonsPrice`, `boardServiceDiscount` to `boardPrice`, `additionalServicesDiscount` to `servicesPrice`. Surcharges and running costs sit in `total` but in no section, so they are never discounted.
+The first three discounts each apply to one section of the breakdown: `accommodationDiscount` to `basePrice + additionalPersonsPrice`, `boardServiceDiscount` to `boardPrice`, `additionalServicesDiscount` to `servicesPrice`. Surcharges, running costs and the lines of split-off periods sit in `total` but in no section, so the section discounts never reach them; only `totalDiscountAmount` does.
+
+`dateFrom`/`dateTo`/`nights` span the whole stay. The office can split nights off its start or end, for example for an advance team arriving before the group. Such a split-off period has no headcount, board or services of its own; it is priced as free-form lines instead. `paxCount`, `minorsCount`, `childrenCount`, `boardService` and `additionalServices` describe the **group**, which stays for what remains between the split-off periods. The split-off periods are listed in `priceBreakdown.periods`, below. A booking nobody split has an empty list there, and its group stays for the whole stay.
 
 `totalDiscountAmount` is a freely named discount on the whole price, labelled by `totalDiscountLabel`. It is a fixed sum, not a percentage, and is subtracted **after** the three section discounts have reduced `total`. It is capped at what is left of that subtotal, so `discountedTotal` is never negative and the amount shown in the breakdown may be smaller than `totalDiscountAmount` itself. The section discounts are each rounded to the nearest cent as they are applied.
 
@@ -570,6 +572,10 @@ The first three discounts each apply to one section of the breakdown: `accommoda
 
 | field | meaning |
 | --- | --- |
+| `nights` | the group's nights, which are fewer than the booking's `nights` when periods were split off |
+| `periods` | list of `{position, label, dateFrom, dateTo, nights, lines, total}`, at most one per side, in date order; `position` is `leading` (before the group) or `trailing` (after it), `label` is the office's name for the period or `null`, `lines` is a list of `{label, amount}`, and `total` is their sum |
+| `periodsTotal` | the sum of all `periods[].total` |
+| `total` | the price before discounts, the group's rows plus `periodsTotal` |
 | `discounts` | list of `{label, percent, amount}` for the section discounts; entries rounding to `0` are omitted, and `label` already includes its `Rabatt ` prefix |
 | `discountSubtotal` | `total` minus the section discounts — present only when `totalDiscountAmount` applies *and* at least one section discount did, otherwise `null` |
 | `totalDiscountDetails` | `{label, amount}` for the total discount, or `null`; `amount` is the capped figure actually subtracted |

migrations/Version20260930150445.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Split-off periods of an accommodation booking. No backfill: a booking without periods is
+ * priced exactly as before.
+ */
+final class Version20260930150445 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Adds accommodation_booking_period for nights split off the start or end of a stay.';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('CREATE TABLE accommodation_booking_period (id INT AUTO_INCREMENT NOT NULL, booking_id INT NOT NULL, position VARCHAR(10) NOT NULL, date_from DATE NOT NULL COMMENT \'(DC2Type:date_immutable)\', date_to DATE NOT NULL COMMENT \'(DC2Type:date_immutable)\', label VARCHAR(255) DEFAULT NULL, price_lines JSON NOT NULL COMMENT \'(DC2Type:json)\', INDEX IDX_ABFCF6B33301C60 (booking_id), PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB');
+        $this->addSql('ALTER TABLE accommodation_booking_period ADD CONSTRAINT FK_ABFCF6B33301C60 FOREIGN KEY (booking_id) REFERENCES accommodation_booking (id) ON DELETE CASCADE');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE accommodation_booking_period DROP FOREIGN KEY FK_ABFCF6B33301C60');
+        $this->addSql('DROP TABLE accommodation_booking_period');
+    }
+}

src/Controller/Admin/AccommodationBooking/EditPeriodController.php

@@ -0,0 +1,81 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\AccommodationBooking;
+
+use App\Entity\Groups\AccommodationBookingPeriod;
+use App\Exception\ImplausibleBookingPriceException;
+use App\Form\Admin\Groups\AccommodationBookingPeriodType;
+use App\Form\Model\AccommodationBookingPeriodDto;
+use App\Htmx\HxTrait;
+use App\Service\AccommodationBookingService;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\Form\FormError;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+/** Changes the length and the lines of a split-off period; the main period absorbs the difference. */
+#[IsGranted('ROLE_GROUPS_MANAGER')]
+class EditPeriodController extends AbstractController
+{
+    use HxTrait;
+    use RedirectsToEditFormTrait;
+
+    public function __construct(
+        private readonly AccommodationBookingService $bookingService,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    #[Route('/admin/accommodation-booking-period/{id}/edit', name: 'app_admin_accommodationbooking_period_edit')]
+    public function index(AccommodationBookingPeriod $period, Request $request): Response
+    {
+        $booking = $period->getBooking() ?? throw $this->createNotFoundException();
+
+        $dto = AccommodationBookingPeriodDto::fromPeriod($period);
+        $form = $this->createForm(AccommodationBookingPeriodType::class, $dto, [
+            'currency' => $booking->getPricingCurrency() ?? $booking->getAccommodation()?->getCurrency() ?? 'EUR',
+            'hx_post' => $request->getRequestUri(),
+        ]);
+        $form->handleRequest($request);
+
+        if ($form->isSubmitted() && $form->isValid()) {
+            try {
+                $violations = $this->bookingService->updatePeriod($booking, $period, $dto);
+
+                foreach ($violations as $violation) {
+                    $form->addError(new FormError((string) $violation->getMessage()));
+                }
+
+                if (0 === count($violations)) {
+                    $this->addFlash('success', 'Der Zeitraum wurde aktualisiert.');
+
+                    $this->logger->info('Updated a period of accommodation booking', [
+                        'id' => $booking->getId(),
+                        'periodId' => $period->getId(),
+                        'nights' => $dto->nights,
+                    ]);
+
+                    return $this->htmxRedirect($request, $this->editUrl($booking, $request));
+                }
+            } catch (ImplausibleBookingPriceException $e) {
+                $this->logger->error('Refused to update a period over an implausible accommodation booking total', [
+                    'exception' => $e,
+                    'id' => $booking->getId(),
+                    'periodId' => $period->getId(),
+                ]);
+                $form->addError(new FormError(ImplausibleBookingPriceException::FORM_ERROR_MESSAGE));
+            }
+        }
+
+        return $this->render('admin/accommodation_booking/modal_period.html.twig', [
+            'booking' => $booking,
+            'form' => $form,
+            'title' => 'Zeitraum bearbeiten',
+        ]);
+    }
+}

src/Controller/Admin/AccommodationBooking/RedirectsToEditFormTrait.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\AccommodationBooking;
+
+use App\Entity\Groups\AccommodationBooking;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * For the modals opened from the edit form: they save on their own and send the browser back to
+ * it, rebuilt with the new price.
+ */
+trait RedirectsToEditFormTrait
+{
+    /**
+     * The return url is forwarded still encoded, the way return_url() handed it over, so that
+     * the edit page keeps leading back to the list the booking was opened from.
+     */
+    private function editUrl(AccommodationBooking $booking, Request $request): string
+    {
+        $parameters = ['id' => $booking->getId()];
+        $returnUrl = $request->query->getString('r');
+        if ('' !== $returnUrl) {
+            $parameters['r'] = $returnUrl;
+        }
+
+        return $this->generateUrl('app_admin_accommodationbooking_edit', $parameters);
+    }
+}

src/Controller/Admin/AccommodationBooking/RemovePeriodController.php

@@ -0,0 +1,80 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\AccommodationBooking;
+
+use App\Entity\Groups\AccommodationBookingPeriod;
+use App\Exception\ImplausibleBookingPriceException;
+use App\Htmx\HxTrait;
+use App\Service\AccommodationBookingService;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+/** Gives a split-off period's nights back to the main period, which reprices the booking. */
+#[IsGranted('ROLE_GROUPS_MANAGER')]
+class RemovePeriodController extends AbstractController
+{
+    use HxTrait;
+    use RedirectsToEditFormTrait;
+
+    public function __construct(
+        private readonly AccommodationBookingService $bookingService,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    #[Route('/admin/accommodation-booking-period/{id}/remove', name: 'app_admin_accommodationbooking_period_remove')]
+    public function index(AccommodationBookingPeriod $period, Request $request): Response
+    {
+        $booking = $period->getBooking() ?? throw $this->createNotFoundException();
+
+        if ($request->isMethod(Request::METHOD_POST)) {
+            if (!$this->isCsrfTokenValid('remove_accommodation_booking_period_'.$period->getId(), $request->request->getString('_token'))) {
+                throw $this->createAccessDeniedException('Invalid CSRF token.');
+            }
+
+            $periodId = $period->getId();
+
+            try {
+                $violations = $this->bookingService->removePeriod($booking, $period);
+            } catch (ImplausibleBookingPriceException $e) {
+                $this->logger->error('Refused to remove a period over an implausible accommodation booking total', [
+                    'exception' => $e,
+                    'id' => $booking->getId(),
+                    'periodId' => $periodId,
+                ]);
+                $this->addFlash('error', ImplausibleBookingPriceException::FORM_ERROR_MESSAGE);
+
+                return $this->htmxRedirect($request, $this->editUrl($booking, $request));
+            }
+
+            // Removing only ever lengthens the main period, so this is reached only when the
+            // stay's dates were already inconsistent with the periods.
+            foreach ($violations as $violation) {
+                $this->addFlash('error', (string) $violation->getMessage());
+            }
+
+            if (0 === count($violations)) {
+                $this->addFlash('success', 'Der Zeitraum wurde entfernt.');
+
+                $this->logger->info('Removed a period of accommodation booking', [
+                    'id' => $booking->getId(),
+                    'periodId' => $periodId,
+                ]);
+            }
+
+            return $this->htmxRedirect($request, $this->editUrl($booking, $request));
+        }
+
+        return $this->render('admin/accommodation_booking/modal_remove_period.html.twig', [
+            'booking' => $booking,
+            'period' => $period,
+            'csrf_token_id' => 'remove_accommodation_booking_period_'.$period->getId(),
+        ]);
+    }
+}

src/Controller/Admin/AccommodationBooking/SplitPeriodController.php

@@ -0,0 +1,107 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Controller\Admin\AccommodationBooking;
+
+use App\Entity\Groups\AccommodationBooking;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
+use App\Exception\ImplausibleBookingPriceException;
+use App\Form\Admin\Groups\AccommodationBookingPeriodType;
+use App\Form\Model\AccommodationBookingPeriodDto;
+use App\Form\Model\AccommodationBookingPeriodLineDto;
+use App\Htmx\HxTrait;
+use App\Service\AccommodationBookingService;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\Form\FormError;
+use Symfony\Component\Form\FormInterface;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+use Symfony\Component\Security\Http\Attribute\IsGranted;
+
+/**
+ * Splits nights off the start or the end of the stay, for a part of the group that arrives
+ * early or leaves late and is quoted as free-form lines instead of the booking's parameters.
+ * Each side can be split once; the period can be resized afterwards through its edit modal.
+ */
+#[IsGranted('ROLE_GROUPS_MANAGER')]
+class SplitPeriodController extends AbstractController
+{
+    use HxTrait;
+    use RedirectsToEditFormTrait;
+
+    public function __construct(
+        private readonly AccommodationBookingService $bookingService,
+        private readonly LoggerInterface $logger,
+    ) {
+    }
+
+    #[Route(
+        '/admin/accommodation-booking/{id}/period/split/{position}',
+        name: 'app_admin_accommodationbooking_period_split',
+        requirements: ['position' => 'leading|trailing'],
+    )]
+    public function index(AccommodationBooking $booking, AccommodationBookingPeriodPosition $position, Request $request): Response
+    {
+        // One period per side. The edit page only offers the free sides, so this catches a page
+        // that was open while somebody else split the same side.
+        if (!$booking->canSplitOffPeriod($position)) {
+            $this->addFlash('error', AccommodationBookingPeriodPosition::Leading === $position
+                ? 'Am Anfang wurde bereits ein Zeitraum abgeteilt.'
+                : 'Am Ende wurde bereits ein Zeitraum abgeteilt.');
+
+            return $this->htmxRedirect($request, $this->editUrl($booking, $request));
+        }
+
+        $dto = new AccommodationBookingPeriodDto(1, [new AccommodationBookingPeriodLineDto()]);
+        $form = $this->createForm(AccommodationBookingPeriodType::class, $dto, [
+            'currency' => $booking->getPricingCurrency() ?? $booking->getAccommodation()?->getCurrency() ?? 'EUR',
+            'hx_post' => $request->getRequestUri(),
+        ]);
+        $form->handleRequest($request);
+
+        if ($form->isSubmitted() && $form->isValid()) {
+            try {
+                $violations = $this->bookingService->splitOffPeriod($booking, $position, $dto);
+
+                foreach ($violations as $violation) {
+                    $form->addError(new FormError((string) $violation->getMessage()));
+                }
+
+                if (0 === count($violations)) {
+                    $this->addFlash('success', 'Der Zeitraum wurde abgeteilt.');
+
+                    $this->logger->info('Split off a period of accommodation booking', [
+                        'id' => $booking->getId(),
+                        'position' => $position->value,
+                        'nights' => $dto->nights,
+                    ]);
+
+                    return $this->htmxRedirect($request, $this->editUrl($booking, $request));
+                }
+            } catch (ImplausibleBookingPriceException $e) {
+                $this->logger->error('Refused to split off a period over an implausible accommodation booking total', [
+                    'exception' => $e,
+                    'id' => $booking->getId(),
+                ]);
+                $form->addError(new FormError(ImplausibleBookingPriceException::FORM_ERROR_MESSAGE));
+            }
+        }
+
+        return $this->renderModal($booking, $position, $form);
+    }
+
+    /** @param FormInterface<AccommodationBookingPeriodDto> $form */
+    private function renderModal(AccommodationBooking $booking, AccommodationBookingPeriodPosition $position, FormInterface $form): Response
+    {
+        return $this->render('admin/accommodation_booking/modal_period.html.twig', [
+            'booking' => $booking,
+            'form' => $form,
+            'title' => AccommodationBookingPeriodPosition::Leading === $position
+                ? 'Zeitraum am Anfang abteilen'
+                : 'Zeitraum am Ende abteilen',
+        ]);
+    }
+}

src/Entity/Groups/AccommodationBooking.php

@@ -10,10 +10,13 @@ use App\Entity\TimestampableEntity;
 use App\Entity\TimestampableEntityInterface;
 use App\Entity\User;
 use App\Enum\Groups\AccommodationBookingOrigin;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
 use App\Enum\Groups\AccommodationBookingStatus;
 use App\Enum\Groups\AdditionalServiceType;
 use App\Exception\ImplausibleBookingPriceException;
 use App\Repository\Groups\AccommodationBookingRepository;
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\DBAL\Types\Types;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Uid\Uuid;
@@ -195,9 +198,21 @@ class AccommodationBooking implements BlameableEntityInterface, TimestampableEnt
     #[ORM\JoinColumn(onDelete: 'SET NULL')]
     private ?User $managedBy = null;
 
+    /**
+     * Nights split off the start or the end of the stay and quoted as free-form lines, at most
+     * one on each side. dateFrom and dateTo keep spanning the whole stay; the booking's own
+     * parameters price only the main period left between the leading and the trailing period.
+     *
+     * @var Collection<int, AccommodationBookingPeriod>
+     */
+    #[ORM\OneToMany(targetEntity: AccommodationBookingPeriod::class, mappedBy: 'booking', cascade: ['persist'], orphanRemoval: true)]
+    #[ORM\OrderBy(['dateFrom' => 'ASC'])]
+    private Collection $periods;
+
     public function __construct()
     {
         $this->uuid = Uuid::v4()->toRfc4122();
+        $this->periods = new ArrayCollection();
     }
 
     /**
@@ -211,10 +226,17 @@ class AccommodationBooking implements BlameableEntityInterface, TimestampableEnt
      * The price snapshot, the service snapshots and all four discounts are deliberately carried
      * over untouched. A copy is made to vary an offer that was already quoted, so it has to show
      * the same numbers as the record it came from rather than a re-quote at today's catalog
-     * prices; saving it through the edit form recomputes it.
+     * prices; saving it through the edit form recomputes it. The split-off periods belong to
+     * that quote and are copied along with it.
      */
     public function __clone()
     {
+        $periods = $this->periods->toArray();
+        $this->periods = new ArrayCollection();
+        foreach ($periods as $period) {
+            $this->addPeriod(clone $period);
+        }
+
         $this->id = null;
         $this->uuid = Uuid::v4()->toRfc4122();
         $this->status = AccommodationBookingStatus::Draft;
@@ -302,6 +324,174 @@ class AccommodationBooking implements BlameableEntityInterface, TimestampableEnt
         }
     }
 
+    /**
+     * At most one period on each side, attached to its edge of the stay, and at least one night
+     * left for the main period in between. A change to the stay's dates that no longer fits the
+     * periods is reported on that date rather than silently moving the periods along.
+     */
+    #[Assert\Callback]
+    public function validatePeriods(ExecutionContextInterface $context): void
+    {
+        if (null === $this->dateFrom || null === $this->dateTo || $this->periods->isEmpty()) {
+            return;
+        }
+
+        foreach (AccommodationBookingPeriodPosition::cases() as $position) {
+            if (count($this->periodsAt($position)) > 1) {
+                $context->buildViolation('Es kann nur einen Zeitraum am Anfang und einen am Ende geben.')
+                    ->addViolation();
+
+                return;
+            }
+        }
+
+        $leading = $this->getLeadingPeriod();
+        if (null !== $leading && (!self::sameDay($leading->getDateFrom(), $this->dateFrom) || $leading->getNights() < 1)) {
+            $context->buildViolation('Der Zeitraum am Anfang passt nicht mehr zur Anreise — bitte Anreise oder Zeitraum prüfen.')
+                ->atPath('dateFrom')
+                ->addViolation();
+
+            return;
+        }
+
+        $trailing = $this->getTrailingPeriod();
+        if (null !== $trailing && (!self::sameDay($trailing->getDateTo(), $this->dateTo) || $trailing->getNights() < 1)) {
+            $context->buildViolation('Der Zeitraum am Ende passt nicht mehr zur Abreise — bitte Abreise oder Zeitraum prüfen.')
+                ->atPath('dateTo')
+                ->addViolation();
+
+            return;
+        }
+
+        if ($this->getMainNights() < 1) {
+            $context->buildViolation('Nach dem Abteilen der Zeiträume muss mindestens eine Nacht für die Gruppe bleiben.')
+                ->atPath('dateTo')
+                ->addViolation();
+        }
+    }
+
+    /** @return Collection<int, AccommodationBookingPeriod> */
+    public function getPeriods(): Collection
+    {
+        return $this->periods;
+    }
+
+    public function addPeriod(AccommodationBookingPeriod $period): self
+    {
+        if (!$this->periods->contains($period)) {
+            $this->periods->add($period);
+            $period->setBooking($this);
+        }
+
+        return $this;
+    }
+
+    public function canSplitOffPeriod(AccommodationBookingPeriodPosition $position): bool
+    {
+        return [] === $this->periodsAt($position);
+    }
+
+    /** Splits $nights off the main period, at the edge of the stay that $position names. */
+    public function splitOffPeriod(AccommodationBookingPeriodPosition $position, int $nights): AccommodationBookingPeriod
+    {
+        if (null === $this->dateFrom || null === $this->dateTo) {
+            throw new \LogicException('A period can only be split off a booking with dates.');
+        }
+
+        if (!$this->canSplitOffPeriod($position)) {
+            throw new \LogicException(sprintf('The booking already has a %s period.', $position->value));
+        }
+
+        $period = new AccommodationBookingPeriod($position, $this->dateFrom, $this->dateTo);
+        $this->addPeriod($period);
+        $this->resizePeriod($period, $nights);
+
+        return $period;
+    }
+
+    /** Gives $period a new length, keeping it at its edge of the stay; the main period absorbs the difference. */
+    public function resizePeriod(AccommodationBookingPeriod $period, int $nights): self
+    {
+        if (null === $this->dateFrom || null === $this->dateTo) {
+            return $this;
+        }
+
+        $period->isLeading()
+            ? $period->setDates($this->dateFrom, $this->dateFrom->modify(sprintf('+%d days', $nights)))
+            : $period->setDates($this->dateTo->modify(sprintf('-%d days', $nights)), $this->dateTo);
+
+        return $this;
+    }
+
+    /** Its nights go back to the main period. */
+    public function removePeriod(AccommodationBookingPeriod $period): self
+    {
+        if ($this->periods->removeElement($period) && $period->getBooking() === $this) {
+            $period->setBooking(null);
+        }
+
+        return $this;
+    }
+
+    public function getLeadingPeriod(): ?AccommodationBookingPeriod
+    {
+        return $this->periodsAt(AccommodationBookingPeriodPosition::Leading)[0] ?? null;
+    }
+
+    public function getTrailingPeriod(): ?AccommodationBookingPeriod
+    {
+        return $this->periodsAt(AccommodationBookingPeriodPosition::Trailing)[0] ?? null;
+    }
+
+    /** Arrival of the group the booking's own parameters price: the stay's, unless a period leads it. */
+    public function getMainDateFrom(): ?\DateTimeImmutable
+    {
+        return $this->getLeadingPeriod()?->getDateTo() ?? $this->dateFrom;
+    }
+
+    /** Departure of the group the booking's own parameters price: the stay's, unless a period trails it. */
+    public function getMainDateTo(): ?\DateTimeImmutable
+    {
+        return $this->getTrailingPeriod()?->getDateFrom() ?? $this->dateTo;
+    }
+
+    public function getMainNights(): int
+    {
+        $from = $this->getMainDateFrom();
+        $to = $this->getMainDateTo();
+
+        if (null === $from || null === $to || $from >= $to) {
+            return 0;
+        }
+
+        return $from->diff($to)->days;
+    }
+
+    /** In minor units, the sum of every line of every split-off period. */
+    public function getPeriodsTotal(): int
+    {
+        $total = 0;
+        foreach ($this->periods as $period) {
+            $total += $period->getTotal();
+        }
+
+        return $total;
+    }
+
+    /** @return list<AccommodationBookingPeriod> */
+    private function periodsAt(AccommodationBookingPeriodPosition $position): array
+    {
+        return array_values(array_filter(
+            $this->periods->toArray(),
+            fn (AccommodationBookingPeriod $p) => $p->getPosition() === $position,
+        ));
+    }
+
+    private static function sameDay(\DateTimeImmutable $a, \DateTimeImmutable $b): bool
+    {
+        return $a->format('Y-m-d') === $b->format('Y-m-d');
+    }
+
     public function getPaxCount(): int
     {
         return $this->paxCount;

src/Entity/Groups/AccommodationBookingPeriod.php

@@ -0,0 +1,155 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Entity\Groups;
+
+use App\Entity\TimestampableEntityInterface;
+use App\Entity\TimestampableParentAwareInterface;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
+use Doctrine\DBAL\Types\Types;
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * A stretch of nights split off the start or the end of a stay, such as the day an advance team
+ * arrives before the group. It carries no pax, board or services of its own and is never priced
+ * from the catalog: the office quotes it as free-form lines, which are added to the booking's
+ * total and fall under its fixed total discount. The booking's own parameters price only what
+ * remains between the leading and the trailing periods.
+ */
+#[ORM\Entity]
+class AccommodationBookingPeriod implements TimestampableParentAwareInterface
+{
+    #[ORM\Id]
+    #[ORM\GeneratedValue]
+    #[ORM\Column]
+    private ?int $id = null;
+
+    #[ORM\ManyToOne(inversedBy: 'periods')]
+    #[ORM\JoinColumn(nullable: false, onDelete: 'CASCADE')]
+    private ?AccommodationBooking $booking = null;
+
+    #[ORM\Column(length: 10, enumType: AccommodationBookingPeriodPosition::class)]
+    private AccommodationBookingPeriodPosition $position;
+
+    #[ORM\Column(type: Types::DATE_IMMUTABLE)]
+    private \DateTimeImmutable $dateFrom;
+
+    // Exclusive, like the booking's: the departure day, not the last night.
+    #[ORM\Column(type: Types::DATE_IMMUTABLE)]
+    private \DateTimeImmutable $dateTo;
+
+    /** What the price breakdown calls the period, e.g. "Vorausteam"; without one it shows the dates alone. */
+    #[ORM\Column(length: 255, nullable: true)]
+    private ?string $label = null;
+
+    /**
+     * Amounts in minor units of the booking's pricing currency; a line has no currency of its own.
+     *
+     * The column is not called `lines`: that is a reserved word in MariaDB, and the ORM does
+     * not quote column names in the statements it writes.
+     *
+     * @var list<array{label: string, amount: int}>
+     */
+    #[ORM\Column(name: 'price_lines', type: Types::JSON)]
+    private array $lines = [];
+
+    public function __construct(AccommodationBookingPeriodPosition $position, \DateTimeImmutable $dateFrom, \DateTimeImmutable $dateTo)
+    {
+        $this->position = $position;
+        $this->dateFrom = $dateFrom;
+        $this->dateTo = $dateTo;
+    }
+
+    public function __clone()
+    {
+        $this->id = null;
+        $this->booking = null;
+    }
+
+    public function getId(): ?int
+    {
+        return $this->id;
+    }
+
+    public function getBooking(): ?AccommodationBooking
+    {
+        return $this->booking;
+    }
+
+    public function setBooking(?AccommodationBooking $booking): self
+    {
+        $this->booking = $booking;
+
+        return $this;
+    }
+
+    public function getTimestampableParent(): ?TimestampableEntityInterface
+    {
+        return $this->booking;
+    }
+
+    public function getPosition(): AccommodationBookingPeriodPosition
+    {
+        return $this->position;
+    }
+
+    public function isLeading(): bool
+    {
+        return AccommodationBookingPeriodPosition::Leading === $this->position;
+    }
+
+    public function getDateFrom(): \DateTimeImmutable
+    {
+        return $this->dateFrom;
+    }
+
+    public function getDateTo(): \DateTimeImmutable
+    {
+        return $this->dateTo;
+    }
+
+    public function setDates(\DateTimeImmutable $dateFrom, \DateTimeImmutable $dateTo): self
+    {
+        $this->dateFrom = $dateFrom;
+        $this->dateTo = $dateTo;
+
+        return $this;
+    }
+
+    public function getLabel(): ?string
+    {
+        return $this->label;
+    }
+
+    public function setLabel(?string $label): self
+    {
+        $this->label = $label;
+
+        return $this;
+    }
+
+    public function getNights(): int
+    {
+        return $this->dateFrom < $this->dateTo ? $this->dateFrom->diff($this->dateTo)->days : 0;
+    }
+
+    /** @return list<array{label: string, amount: int}> */
+    public function getLines(): array
+    {
+        return $this->lines;
+    }
+
+    /** @param list<array{label: string, amount: int}> $lines */
+    public function setLines(array $lines): self
+    {
+        $this->lines = $lines;
+
+        return $this;
+    }
+
+    public function getTotal(): int
+    {
+        return array_sum(array_column($this->lines, 'amount'));
+    }
+}

src/Enum/Groups/AccommodationBookingPeriodPosition.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace App\Enum\Groups;
+
+/**
+ * Which edge of the stay a split-off period sits at. Periods only ever come off the start or
+ * the end, so the main period — the one the booking's own parameters price — always stays a
+ * single contiguous range between them.
+ */
+enum AccommodationBookingPeriodPosition: string
+{
+    case Leading = 'leading';
+    case Trailing = 'trailing';
+}

src/Form/Admin/Groups/AccommodationBookingPeriodLineType.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form\Admin\Groups;
+
+use App\Form\Model\AccommodationBookingPeriodLineDto;
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Extension\Core\Type\MoneyType;
+use Symfony\Component\Form\Extension\Core\Type\TextType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+/** @extends AbstractType<AccommodationBookingPeriodLineDto> */
+class AccommodationBookingPeriodLineType extends AbstractType
+{
+    public function buildForm(FormBuilderInterface $builder, array $options): void
+    {
+        $builder
+            ->add('label', TextType::class, [
+                'label' => 'Bezeichnung',
+            ])
+            ->add('amount', MoneyType::class, [
+                'label' => 'Betrag',
+                'currency' => $options['currency'],
+                'divisor' => 100,
+            ])
+        ;
+    }
+
+    public function configureOptions(OptionsResolver $resolver): void
+    {
+        $resolver->setDefaults([
+            'data_class' => AccommodationBookingPeriodLineDto::class,
+            'empty_data' => static fn () => new AccommodationBookingPeriodLineDto(),
+            'currency' => 'EUR',
+        ]);
+        $resolver->setAllowedTypes('currency', 'string');
+    }
+}

src/Form/Admin/Groups/AccommodationBookingPeriodType.php

@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form\Admin\Groups;
+
+use App\Form\Model\AccommodationBookingPeriodDto;
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Extension\Core\Type\CollectionType;
+use Symfony\Component\Form\Extension\Core\Type\IntegerType;
+use Symfony\Component\Form\Extension\Core\Type\TextType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+/** @extends AbstractType<AccommodationBookingPeriodDto> */
+class AccommodationBookingPeriodType extends AbstractType
+{
+    public function buildForm(FormBuilderInterface $builder, array $options): void
+    {
+        $builder
+            ->add('label', TextType::class, [
+                'label' => 'Bezeichnung',
+                'required' => false,
+                'help' => 'Überschrift in der Preisaufstellung, z. B. „Vorausteam“. Ohne Bezeichnung steht dort nur der Zeitraum.',
+            ])
+            ->add('nights', IntegerType::class, [
+                'label' => 'Nächte',
+                'attr' => ['min' => 1],
+            ])
+            ->add('lines', CollectionType::class, [
+                'label' => 'Positionen',
+                'entry_type' => AccommodationBookingPeriodLineType::class,
+                'entry_options' => ['label' => false, 'currency' => $options['currency']],
+                'allow_add' => true,
+                'allow_delete' => true,
+                'by_reference' => false,
+                'prototype' => true,
+            ])
+        ;
+    }
+
+    public function configureOptions(OptionsResolver $resolver): void
+    {
+        $resolver->setDefaults([
+            'data_class' => AccommodationBookingPeriodDto::class,
+            'currency' => 'EUR',
+        ]);
+        $resolver->setAllowedTypes('currency', 'string');
+    }
+}

src/Form/Model/AccommodationBookingPeriodDto.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form\Model;
+
+use App\Entity\Groups\AccommodationBooking;
+use App\Entity\Groups\AccommodationBookingPeriod;
+use Symfony\Component\Validator\Constraints as Assert;
+
+/**
+ * What the split and edit modals submit for a split-off period. Whether the group keeps a
+ * night for itself depends on the booking, so that is left to the booking's own validation.
+ */
+class AccommodationBookingPeriodDto
+{
+    /**
+     * @param array<int, AccommodationBookingPeriodLineDto> $lines keyed as the form submits them, so not necessarily a list
+     */
+    public function __construct(
+        #[Assert\NotNull(message: 'Bitte die Anzahl der Nächte angeben.')]
+        #[Assert\Range(min: 1, max: AccommodationBooking::MAX_NIGHTS)]
+        public ?int $nights = 1,
+        #[Assert\Valid]
+        public array $lines = [],
+        #[Assert\Length(max: 255)]
+        public ?string $label = null,
+    ) {
+    }
+
+    public static function fromPeriod(AccommodationBookingPeriod $period): self
+    {
+        return new self(
+            $period->getNights(),
+            array_map(
+                fn (array $line) => new AccommodationBookingPeriodLineDto($line['label'], $line['amount']),
+                $period->getLines(),
+            ),
+            $period->getLabel(),
+        );
+    }
+
+    /** @return list<array{label: string, amount: int}> */
+    public function linesSnapshot(): array
+    {
+        return array_values(array_map(
+            fn (AccommodationBookingPeriodLineDto $line) => ['label' => (string) $line->label, 'amount' => (int) $line->amount],
+            $this->lines,
+        ));
+    }
+}

src/Form/Model/AccommodationBookingPeriodLineDto.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form\Model;
+
+use Symfony\Component\Validator\Constraints as Assert;
+
+/** One free-form price line of a split-off period, as the office keys it in. */
+class AccommodationBookingPeriodLineDto
+{
+    public function __construct(
+        #[Assert\NotBlank(message: 'Bitte eine Bezeichnung angeben.')]
+        #[Assert\Length(max: 255)]
+        public ?string $label = null,
+        /** In minor units of the booking's pricing currency. */
+        #[Assert\NotNull(message: 'Bitte einen Betrag angeben.')]
+        #[Assert\PositiveOrZero]
+        public ?int $amount = null,
+    ) {
+    }
+}

src/Service/AccommodationBookingBreakdownCalculator.php

@@ -26,7 +26,15 @@ class AccommodationBookingBreakdownCalculator
     {
         $breakdown = $booking->getPriceBreakdown() ?? $this->computeCurrent($booking);
 
-        return null !== $breakdown ? $this->withDiscounts($booking, $breakdown) : null;
+        if (null === $breakdown) {
+            return null;
+        }
+
+        // Snapshots frozen before split-off periods existed (pricing version 1) read as a
+        // booking without any, so templates only ever handle one shape.
+        $breakdown += ['periods' => [], 'periodsTotal' => 0];
+
+        return $this->withDiscounts($booking, $breakdown);
     }
 
     /**
@@ -100,6 +108,10 @@ class AccommodationBookingBreakdownCalculator
      * Calculates against the current catalog. Use only while creating or explicitly editing
      * a booking, or as a compatibility fallback for records created before price snapshots.
      *
+     * The catalog prices the main period only; the split-off periods add their lines on top,
+     * so `total` is the grand total the discounts are taken from. The price rows are loaded for
+     * the whole stay, which the includedPax floor and the short-term surcharge are judged on.
+     *
      * @return array<string, mixed>|null
      */
     public function computeCurrent(AccommodationBooking $booking): ?array
@@ -118,16 +130,40 @@ class AccommodationBookingBreakdownCalculator
             $dateTo,
         );
 
-        return $this->priceCalculator->calculateFromSnapshots(
+        $breakdown = $this->priceCalculator->calculateFromSnapshots(
             $booking->getPaxCount(),
             $booking->getMinorsCount(),
-            $booking->getNights(),
+            $booking->getMainNights(),
+            $booking->getMainDateFrom() ?? $dateFrom,
+            $booking->getMainDateTo() ?? $dateTo,
             $dateFrom,
-            $dateTo,
+            $booking->getNights(),
             $prices,
             $booking->getBoardServicePrice(),
             $booking->getAdditionalServices(),
             $accommodation->getCurrency(),
         );
+
+        $periods = [];
+        foreach (array_filter([$booking->getLeadingPeriod(), $booking->getTrailingPeriod()]) as $period) {
+            $periods[] = [
+                'position' => $period->getPosition()->value,
+                'label' => $period->getLabel(),
+                'dateFrom' => $period->getDateFrom()->format('Y-m-d'),
+                'dateTo' => $period->getDateTo()->format('Y-m-d'),
+                'nights' => $period->getNights(),
+                'lines' => $period->getLines(),
+                'total' => $period->getTotal(),
+            ];
+        }
+
+        $periodsTotal = $booking->getPeriodsTotal();
+
+        return [
+            ...$breakdown,
+            'periods' => $periods,
+            'periodsTotal' => $periodsTotal,
+            'total' => $breakdown['total'] + $periodsTotal,
+        ];
     }
 }

src/Service/AccommodationBookingService.php

@@ -8,13 +8,16 @@ use App\Email\EmailAttachmentInterface;
 use App\Email\Mailer;
 use App\Entity\Groups\Accommodation;
 use App\Entity\Groups\AccommodationBooking;
+use App\Entity\Groups\AccommodationBookingPeriod;
 use App\Entity\Groups\AccommodationPrice;
 use App\Entity\Groups\AdditionalService;
 use App\Entity\Groups\BoardService;
 use App\Enum\Groups\AccommodationBookingOrigin;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
 use App\Enum\Groups\AccommodationBookingStatus;
 use App\Exception\ImplausibleBookingPriceException;
 use App\Form\Model\AccommodationBookingDto;
+use App\Form\Model\AccommodationBookingPeriodDto;
 use App\Model\AccommodationBookingContext;
 use App\Model\AccommodationBookingQueryParams;
 use App\Model\CmsHotelData;
@@ -25,11 +28,16 @@ use App\Repository\Groups\AdditionalServiceRepository;
 use App\Repository\Groups\BoardServiceRepository;
 use Doctrine\ORM\EntityManagerInterface;
 use Psr\Log\LoggerInterface;
+use Symfony\Component\Validator\ConstraintViolationListInterface;
 use Symfony\Component\Validator\Validator\ValidatorInterface;
 
 class AccommodationBookingService
 {
-    private const int PRICING_VERSION = 1;
+    /**
+     * 2: the breakdown carries the split-off `periods` and `periodsTotal`, and `total` includes
+     * them. Version 1 snapshots are read as bookings without periods.
+     */
+    private const int PRICING_VERSION = 2;
 
     public function __construct(
         private readonly AccommodationRepository $accommodationRepo,
@@ -381,6 +389,54 @@ class AccommodationBookingService
         );
     }
 
+    /**
+     * The three period changes below each take effect at once, like the house change: they
+     * reprice the booking, and the office wants to see the new price before it goes on.
+     * On violations nothing is written and the violations are returned for the modal.
+     *
+     * @throws ImplausibleBookingPriceException if the new total is too large to be a real price
+     */
+    public function splitOffPeriod(AccommodationBooking $booking, AccommodationBookingPeriodPosition $position, AccommodationBookingPeriodDto $dto): ConstraintViolationListInterface
+    {
+        $booking->splitOffPeriod($position, (int) $dto->nights)
+            ->setLabel($dto->label)
+            ->setLines($dto->linesSnapshot());
+
+        return $this->commitPeriodChange($booking);
+    }
+
+    /** @throws ImplausibleBookingPriceException if the new total is too large to be a real price */
+    public function updatePeriod(AccommodationBooking $booking, AccommodationBookingPeriod $period, AccommodationBookingPeriodDto $dto): ConstraintViolationListInterface
+    {
+        $booking->resizePeriod($period, (int) $dto->nights);
+        $period->setLabel($dto->label)->setLines($dto->linesSnapshot());
+
+        return $this->commitPeriodChange($booking);
+    }
+
+    /** @throws ImplausibleBookingPriceException if the new total is too large to be a real price */
+    public function removePeriod(AccommodationBooking $booking, AccommodationBookingPeriod $period): ConstraintViolationListInterface
+    {
+        $booking->removePeriod($period);
+
+        return $this->commitPeriodChange($booking);
+    }
+
+    private function commitPeriodChange(AccommodationBooking $booking): ConstraintViolationListInterface
+    {
+        // Default only: the `edit` group asks for contact data, which a period change neither
+        // shows nor touches, and which the edit form already enforces where it belongs.
+        $violations = $this->validator->validate($booking, null, ['Default']);
+        if (count($violations) > 0) {
+            return $violations;
+        }
+
+        $this->refreshPriceSnapshot($booking);
+        $this->entityManager->flush();
+
+        return $violations;
+    }
+
     public function sendNotificationEmail(AccommodationBooking $booking): void
     {
         $this->sendBookingEmail(

src/Service/GroupsPriceCalculator.php

@@ -86,6 +86,8 @@ class GroupsPriceCalculator
             $nights,
             $dateFrom,
             $dateTo,
+            $dateFrom,
+            $nights,
             $prices,
             $boardService?->getPrice(),
             array_map(
@@ -104,7 +106,12 @@ class GroupsPriceCalculator
      * Same calculation but using frozen snapshot data from an AccommodationBooking entity
      * instead of live catalog entities.
      *
-     * @param AccommodationPrice[]                                                              $prices                     all prices overlapping the booking window
+     * $dateFrom/$dateTo/$nights are the nights being priced, which is the main period of a booking
+     * with split-off periods. $stayDateFrom and $stayNights describe the whole stay, which the
+     * includedPax floor and the short-term surcharge are judged on, so that splitting nights off
+     * never changes either.
+     *
+     * @param AccommodationPrice[]                                                              $prices                     all prices overlapping the whole stay
      * @param list<array{label: string, price: int, type: string, originalServiceId: int|null}> $additionalServiceSnapshots
      *
      * @return array{
@@ -131,6 +138,8 @@ class GroupsPriceCalculator
         int $nights,
         \DateTimeImmutable $dateFrom,
         \DateTimeImmutable $dateTo,
+        \DateTimeImmutable $stayDateFrom,
+        int $stayNights,
         array $prices,
         ?int $boardServicePricePerPersonNight,
         array $additionalServiceSnapshots,
@@ -151,6 +160,8 @@ class GroupsPriceCalculator
             $nights,
             $dateFrom,
             $dateTo,
+            $stayDateFrom,
+            $stayNights,
             $prices,
             $boardServicePricePerPersonNight,
             $items,
@@ -186,15 +197,19 @@ class GroupsPriceCalculator
         int $nights,
         \DateTimeImmutable $dateFrom,
         \DateTimeImmutable $dateTo,
+        \DateTimeImmutable $stayDateFrom,
+        int $stayNights,
         array $prices,
         ?int $boardServicePricePerPersonNight,
         array $additionalItems,
         string $currency,
     ): array {
-        // Derive effectivePax: children 0–3 don't count, but never drop below includedPax
+        // Derive effectivePax: children 0–3 don't count, but never drop below includedPax.
+        // The floor comes from the stay's first night, not the priced range's, so that splitting
+        // nights off the start cannot swap in another price row's floor.
         $firstCandidates = array_values(array_filter(
             $prices,
-            fn (AccommodationPrice $p) => $p->getDateFrom() <= $dateFrom && $p->getDateTo() >= $dateFrom,
+            fn (AccommodationPrice $p) => $p->getDateFrom() <= $stayDateFrom && $p->getDateTo() >= $stayDateFrom,
         ));
         $firstWinner = $this->priceTimelineBuilder->resolveWinner($firstCandidates);
         $includedPaxFloor = $firstWinner?->getIncludedPax() ?? 1;
@@ -239,10 +254,10 @@ class GroupsPriceCalculator
             }
         }
 
-        // Rule 3: short-term surcharge
+        // Rule 3: short-term surcharge, judged on the whole stay but charged on the priced nights
         $shortTermSurcharge = 0;
-        if (isset(self::SHORT_TERM_FACTORS[$nights])) {
-            $shortTermSurcharge = (int) round(($basePrice + $additionalPersonsPrice) * self::SHORT_TERM_FACTORS[$nights] / 100);
+        if (isset(self::SHORT_TERM_FACTORS[$stayNights])) {
+            $shortTermSurcharge = (int) round(($basePrice + $additionalPersonsPrice) * self::SHORT_TERM_FACTORS[$stayNights] / 100);
         }
 
         // Board is only billable — and only triggers the catering surcharge — when it costs

templates/admin/accommodation_booking/edit.html.twig

@@ -41,6 +41,48 @@
         {{ form_row(form.minorsCount) }}
         {{ form_row(form.childrenCount) }}
 
+        {# Saved by their own modals, which reprice the booking on the spot — see SplitPeriodController. #}
+        <div class="lg:col-span-2">
+            <h3 class="font-bold pb-1">Zeiträume</h3>
+            <p class="text-xs text-gray-500 pb-2">
+                Anreise und Abreise umfassen den ganzen Aufenthalt. Abgeteilte Zeiträume, etwa für ein
+                Vorausteam, werden mit eigenen Positionen berechnet; Personen und Leistungen oben gelten
+                nur für den Zeitraum der Gruppe.
+            </p>
+            <table class="w-full text-sm">
+                {% if booking.leadingPeriod %}
+                    {% set p = booking.leadingPeriod %}
+                    {{ block('period_row') }}
+                {% endif %}
+                <tr class="border-t border-gray-200">
+                    <td class="py-1 whitespace-nowrap">{{ booking.mainDateFrom | date('d.m.Y') }} – {{ booking.mainDateTo | date('d.m.Y') }}</td>
+                    <td class="py-1 whitespace-nowrap">{{ booking.mainNights }} {{ booking.mainNights != 1 ? 'Nächte' : 'Nacht' }}</td>
+                    <td class="py-1" colspan="2">Gruppe</td>
+                    <td class="py-1 text-right">
+                        {# One period per side, so only the free sides are offered. #}
+                        {% if booking.leadingPeriod is null or booking.trailingPeriod is null %}
+                            <twig:dropdown>
+                                {% if booking.leadingPeriod is null %}
+                                    <twig:dropdown:hxbutton url="{{ path('app_admin_accommodationbooking_period_split', back_params | merge({ position: 'leading' })) }}">
+                                        am Anfang abteilen
+                                    </twig:dropdown:hxbutton>
+                                {% endif %}
+                                {% if booking.trailingPeriod is null %}
+                                    <twig:dropdown:hxbutton url="{{ path('app_admin_accommodationbooking_period_split', back_params | merge({ position: 'trailing' })) }}">
+                                        am Ende abteilen
+                                    </twig:dropdown:hxbutton>
+                                {% endif %}
+                            </twig:dropdown>
+                        {% endif %}
+                    </td>
+                </tr>
+                {% if booking.trailingPeriod %}
+                    {% set p = booking.trailingPeriod %}
+                    {{ block('period_row') }}
+                {% endif %}
+            </table>
+        </div>
+
         {% if form.boardService is defined or form.selectedAdditionalServices is defined %}
             <h2 class="lg:col-span-2 text-base font-bold pt-2">Leistungen</h2>
             {% if form.boardService is defined %}
@@ -98,3 +140,37 @@
     {{ form_rest(form) }}
     {{ form_end(form) }}
 {% endblock %}
+
+{% block period_row %}
+    {% set period_params = { id: p.id } %}
+    {% if app.request.query.get('r') %}
+        {% set period_params = period_params | merge({ r: app.request.query.get('r') }) %}
+    {% endif %}
+    <tr class="border-t border-gray-200 align-top">
+        <td class="py-1 whitespace-nowrap">{{ p.dateFrom | date('d.m.Y') }} – {{ p.dateTo | date('d.m.Y') }}</td>
+        <td class="py-1 whitespace-nowrap">{{ p.nights }} {{ p.nights != 1 ? 'Nächte' : 'Nacht' }}</td>
+        <td class="py-1">
+            {% if p.label %}
+                <div class="font-medium">{{ p.label }}</div>
+            {% endif %}
+            {% for line in p.lines %}
+                <div>{{ line.label }}</div>
+            {% else %}
+                <div class="text-gray-500">keine Positionen</div>
+            {% endfor %}
+        </td>
+        <td class="py-1 text-right whitespace-nowrap">
+            {{ (p.total / 100) | format_currency(booking.pricingCurrency ?? booking.accommodation.currency) }}
+        </td>
+        <td class="py-1 text-right">
+            <twig:dropdown>
+                <twig:dropdown:hxbutton url="{{ path('app_admin_accommodationbooking_period_edit', period_params) }}">
+                    bearbeiten
+                </twig:dropdown:hxbutton>
+                <twig:dropdown:hxbutton url="{{ path('app_admin_accommodationbooking_period_remove', period_params) }}" warning>
+                    entfernen
+                </twig:dropdown:hxbutton>
+            </twig:dropdown>
+        </td>
+    </tr>
+{% endblock %}

templates/admin/accommodation_booking/modal_period.html.twig

@@ -0,0 +1,57 @@
+{% extends 'htmx_modal_admin.html.twig' %}
+{% form_theme form 'forms_admin.html.twig' %}
+
+{% macro line_row(line) %}
+    <div class="flex items-start gap-2" data-form-collection-target="field">
+        <div class="flex-1">{{ form_row(line.label) }}</div>
+        <div class="w-40">{{ form_row(line.amount) }}</div>
+        <button type="button"
+                class="mt-9 text-gray-500 hover:text-red-500"
+                data-action="form-collection#removeItem"
+                title="Position entfernen">
+            {{ icon('close', 'w-5 h-5') }}
+        </button>
+    </div>
+{% endmacro %}
+
+{% block content %}
+    {% import _self as period %}
+    <div class="text-xl font-bold pb-4">
+        {{ title }}
+    </div>
+    <p class="text-sm text-gray-500 pb-4">
+        Die Nächte werden vom Zeitraum der Gruppe abgezogen, der neu berechnet wird. Die Positionen
+        kommen zum Gesamtpreis hinzu und fallen nur unter den Rabatt auf den Gesamtpreis.
+    </p>
+    {{ form_start(form) }}
+    {{ form_errors(form) }}
+    <div class="pb-4">
+        {{ form_row(form.label) }}
+    </div>
+    <div class="w-40 pb-4">
+        {{ form_row(form.nights) }}
+    </div>
+    {% set prototype %}{{ period.line_row(form.lines.vars.prototype) }}{% endset %}
+    <div {{ stimulus_controller('form-collection', { prototype: prototype|json_encode }) }}>
+        <div class="font-bold pb-2">Positionen</div>
+        {{ form_errors(form.lines) }}
+        <div class="space-y-2" data-form-collection-target="fields">
+            {% for line in form.lines %}
+                {{ period.line_row(line) }}
+            {% endfor %}
+        </div>
+        <button type="button"
+                class="button button--secondary button--small mt-2"
+                data-action="form-collection#addItem">
+            Position hinzufügen
+        </button>
+    </div>
+    {% do form.lines.setRendered %}
+    <div class="flex justify-end pt-8">
+        <button type="submit" class="button button--primary button--small">
+            speichern
+        </button>
+    </div>
+    {{ form_rest(form) }}
+    {{ form_end(form) }}
+{% endblock %}

templates/admin/accommodation_booking/modal_remove_period.html.twig

@@ -0,0 +1,13 @@
+{% extends 'htmx_confirmation_modal.html.twig' %}
+
+{% block title %}Zeitraum entfernen{% endblock %}
+
+{% block content %}
+    <div>
+        Möchtest du den Zeitraum {{ period.dateFrom | date('d.m.Y') }} – {{ period.dateTo | date('d.m.Y') }}
+        mit allen Positionen entfernen? Die Nächte gehen an den Zeitraum der Gruppe zurück, und der
+        Preis wird neu berechnet.
+    </div>
+{% endblock %}
+
+{% block button_confirm %}entfernen{% endblock %}

templates/admin/accommodation_booking/show.html.twig

@@ -43,6 +43,13 @@
                 <dd>{{ booking.dateTo | date('d.m.Y') }}</dd>
                 <dt class="font-medium">Nächte</dt>
                 <dd>{{ booking.nights }}</dd>
+                {% if booking.periods is not empty %}
+                    <dt class="font-medium">Zeitraum Gruppe</dt>
+                    <dd>
+                        {{ booking.mainDateFrom | date('d.m.Y') }} – {{ booking.mainDateTo | date('d.m.Y') }},
+                        {{ booking.mainNights }} {{ booking.mainNights != 1 ? 'Nächte' : 'Nacht' }}
+                    </dd>
+                {% endif %}
                 <dt class="font-medium">Anzahl Personen</dt>
                 <dd>{{ booking.paxCount }}</dd>
                 {% if booking.minorsCount > 0 %}
@@ -89,6 +96,17 @@
                 <h2 class="text-lg font-bold mb-4">Preise</h2>
                 {% set currency = booking.pricingCurrency ?? priceBreakdown.currency %}
                 <table class="w-full text-sm">
+                    {% for period in priceBreakdown.periods | filter(p => p.position == 'leading') %}
+                        {{ block('period_rows') }}
+                    {% endfor %}
+                    {% if priceBreakdown.periods is not empty %}
+                        <tr class="border-t border-gray-200 font-medium">
+                            <td class="pt-2 pb-1" colspan="2">
+                                Gruppe · {{ booking.mainDateFrom | date('d.m.Y') }} – {{ booking.mainDateTo | date('d.m.Y') }},
+                                {{ priceBreakdown.nights }} {{ priceBreakdown.nights != 1 ? 'Nächte' : 'Nacht' }}
+                            </td>
+                        </tr>
+                    {% endif %}
                     {% if priceBreakdown.basePrice > 0 %}
                         <tr>
                             <td class="py-1">
@@ -139,6 +157,9 @@
                             <td class="py-1 text-right whitespace-nowrap">{{ (priceBreakdown.runningCosts / 100) | format_currency(currency) }}</td>
                         </tr>
                     {% endif %}
+                    {% for period in priceBreakdown.periods | filter(p => p.position == 'trailing') %}
+                        {{ block('period_rows') }}
+                    {% endfor %}
                     <tr class="border-t border-gray-200 font-semibold">
                         <td class="pt-2">
                             Gesamtpreis
@@ -304,3 +325,20 @@
         </div>
     </div>
 {% endblock %}
+
+{# One split-off period of the breakdown: its range as a heading, then its lines. #}
+{% block period_rows %}
+    <tr class="border-t border-gray-200 font-medium">
+        <td class="pt-2 pb-1" colspan="2">
+            {% if period.label ?? null %}{{ period.label }} · {% endif %}
+            {{ period.dateFrom | date('d.m.Y') }} – {{ period.dateTo | date('d.m.Y') }},
+            {{ period.nights }} {{ period.nights != 1 ? 'Nächte' : 'Nacht' }}
+        </td>
+    </tr>
+    {% for line in period.lines %}
+        <tr>
+            <td class="py-1">{{ line.label }}</td>
+            <td class="py-1 text-right whitespace-nowrap">{{ (line.amount / 100) | format_currency(currency) }}</td>
+        </tr>
+    {% endfor %}
+{% endblock %}

templates/email/_price_breakdown.html.twig

@@ -11,6 +11,17 @@
     <h2>Preise</h2>
 
     <table style="width: 100%; border-collapse: collapse; font-size: 14px;">
+        {% for period in priceBreakdown.periods|filter(p => p.position == 'leading') %}
+            {% include 'email/_price_breakdown_period.html.twig' %}
+        {% endfor %}
+        {% if priceBreakdown.periods is not empty %}
+            <tr>
+                <td colspan="2" style="{{ cell }} border-top: 1px solid #d1d5db; font-weight: bold;">
+                    Gruppe · {{ booking.mainDateFrom|date('d.m.Y') }} – {{ booking.mainDateTo|date('d.m.Y') }},
+                    {{ priceBreakdown.nights }} {{ priceBreakdown.nights != 1 ? 'Nächte' : 'Nacht' }}
+                </td>
+            </tr>
+        {% endif %}
         {% if priceBreakdown.basePrice > 0 %}
             <tr>
                 <td style="{{ cell }}">
@@ -64,6 +75,9 @@
                 <td style="{{ amount }}">{{ (priceBreakdown.runningCosts / 100)|format_currency(currency) }}</td>
             </tr>
         {% endif %}
+        {% for period in priceBreakdown.periods|filter(p => p.position == 'trailing') %}
+            {% include 'email/_price_breakdown_period.html.twig' %}
+        {% endfor %}
         <tr>
             <td style="{{ cell }} border-top: 1px solid #d1d5db; font-weight: bold;">
                 Gesamtpreis
@@ -103,3 +117,4 @@
         {% endif %}
     </table>
 {% endif %}
+

templates/email/_price_breakdown_period.html.twig

@@ -0,0 +1,15 @@
+{#- One split-off period of _price_breakdown.html.twig: its range as a heading, then its lines.
+    Context: period, cell, amount, currency. -#}
+<tr>
+    <td colspan="2" style="{{ cell }} border-top: 1px solid #d1d5db; font-weight: bold;">
+        {% if period.label ?? null %}{{ period.label }} · {% endif %}
+        {{ period.dateFrom|date('d.m.Y') }} – {{ period.dateTo|date('d.m.Y') }},
+        {{ period.nights }} {{ period.nights != 1 ? 'Nächte' : 'Nacht' }}
+    </td>
+</tr>
+{% for line in period.lines %}
+    <tr>
+        <td style="{{ cell }}">{{ line.label }}</td>
+        <td style="{{ amount }}">{{ (line.amount / 100)|format_currency(currency) }}</td>
+    </tr>
+{% endfor %}

templates/email/_stay_details.html.twig

@@ -19,6 +19,12 @@
         <td><strong>Nächte</strong></td>
         <td>{{ booking.nights }}</td>
     </tr>
+    {% if booking.periods is not empty %}
+        <tr>
+            <td><strong>Zeitraum Gruppe</strong></td>
+            <td>{{ booking.mainDateFrom|date('d.m.Y') }} – {{ booking.mainDateTo|date('d.m.Y') }}</td>
+        </tr>
+    {% endif %}
     <tr>
         <td><strong>Anzahl Personen</strong></td>
         <td>{{ booking.paxCount }}</td>

templates/groups/offer/_summary.html.twig

@@ -67,6 +67,16 @@
                             {{ booking.nights }} {{ booking.nights != 1 ? 'Nächte' : 'Nacht' }}
                         </td>
                     </tr>
+                    {% if ctx.priceBreakdown.periods is not empty %}
+                        <tr>
+                            <td class="p-2">Zeitraum Gruppe</td>
+                            <td class="p-2 text-right">
+                                {{ booking.mainDateFrom|date('d.m.Y') }} – {{ booking.mainDateTo|date('d.m.Y') }},
+                                <br>
+                                {{ ctx.priceBreakdown.nights }} {{ ctx.priceBreakdown.nights != 1 ? 'Nächte' : 'Nacht' }}
+                            </td>
+                        </tr>
+                    {% endif %}
                     <tr>
                         <td class="p-2">
                             Anzahl Personen
@@ -88,6 +98,14 @@
                         </tr>
                     {% endif %}
 
+                    {% for period in ctx.priceBreakdown.periods|filter(p => p.position == 'leading') %}
+                        {% include 'groups/offer/_summary_period.html.twig' %}
+                    {% endfor %}
+                    {% if ctx.priceBreakdown.periods is not empty %}
+                        <tr class="border-t border-primary-bg font-semibold">
+                            <td class="p-2" colspan="2">Gruppe</td>
+                        </tr>
+                    {% endif %}
                     {% if ctx.priceBreakdown.basePrice > 0 %}
                         <tr>
                             <td class="p-2">
@@ -141,6 +159,9 @@
                             <td class="p-2 text-right whitespace-nowrap">{{ (ctx.priceBreakdown.runningCosts / 100)|format_currency(currency) }}</td>
                         </tr>
                     {% endif %}
+                    {% for period in ctx.priceBreakdown.periods|filter(p => p.position == 'trailing') %}
+                        {% include 'groups/offer/_summary_period.html.twig' %}
+                    {% endfor %}
                     <tr class="border-t border-primary-bg font-semibold text-base">
                         <td class="p-2">
                             Gesamtpreis

templates/groups/offer/_summary_period.html.twig

@@ -0,0 +1,15 @@
+{#- One split-off period of the offer summary: its range as a heading, then its lines.
+    Context: period, currency. -#}
+<tr class="border-t border-primary-bg font-semibold">
+    <td class="p-2" colspan="2">
+        {% if period.label ?? null %}{{ period.label }} · {% endif %}
+        {{ period.dateFrom|date('d.m.Y') }} – {{ period.dateTo|date('d.m.Y') }},
+        {{ period.nights }} {{ period.nights != 1 ? 'Nächte' : 'Nacht' }}
+    </td>
+</tr>
+{% for line in period.lines %}
+    <tr>
+        <td class="p-2">{{ line.label }}</td>
+        <td class="p-2 text-right whitespace-nowrap">{{ (line.amount / 100)|format_currency(currency) }}</td>
+    </tr>
+{% endfor %}

templates/pdf/accommodation_booking.html.twig

@@ -83,6 +83,9 @@
                     <tr><th>Anreise</th><td>{{ booking.dateFrom|date('d.m.Y') }}</td></tr>
                     <tr><th>Abreise</th><td>{{ booking.dateTo|date('d.m.Y') }}</td></tr>
                     <tr><th>Nächte</th><td>{{ booking.nights }}</td></tr>
+                    {% if booking.periods is not empty %}
+                        <tr><th>Zeitraum Gruppe</th><td>{{ booking.mainDateFrom|date('d.m.Y') }} – {{ booking.mainDateTo|date('d.m.Y') }}</td></tr>
+                    {% endif %}
                     <tr><th>Anzahl Personen</th><td>{{ booking.paxCount }}</td></tr>
                     {% if booking.minorsCount > 0 %}
                         <tr><th>davon Kinder (0–3 J.)</th><td>{{ booking.minorsCount }}</td></tr>

tests/Controller/Admin/AccommodationBooking/EditPeriodControllerTest.php

@@ -0,0 +1,103 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Controller\Admin\AccommodationBooking;
+
+use App\Controller\Admin\AccommodationBooking\EditPeriodController;
+use App\Entity\Groups\AccommodationBooking;
+use App\Entity\Groups\AccommodationBookingPeriod;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
+use App\Service\AccommodationBookingService;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\Form\FormInterface;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\Validator\ConstraintViolationList;
+
+/** The modal's error handling is shared with SplitPeriodController and covered there. */
+class EditPeriodControllerTest extends TestCase
+{
+    public function testAValidSubmitUpdatesThePeriodOfItsOwnBooking(): void
+    {
+        $booking = (new AccommodationBooking())
+            ->setDateFrom(new \DateTimeImmutable('2026-07-01'))
+            ->setDateTo(new \DateTimeImmutable('2026-07-08'));
+        $period = $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Trailing, 1);
+
+        $bookingService = $this->createMock(AccommodationBookingService::class);
+        $bookingService->expects(self::once())->method('updatePeriod')
+            ->with($booking, $period)
+            ->willReturn(new ConstraintViolationList());
+
+        $form = $this->createStub(FormInterface::class);
+        $form->method('handleRequest')->willReturn($form);
+        $form->method('isSubmitted')->willReturn(true);
+        $form->method('isValid')->willReturn(true);
+
+        $controller = new TestableEditPeriodController($bookingService, $this->createStub(LoggerInterface::class), $form);
+
+        $response = $controller->index($period, Request::create('/admin/accommodation-booking-period/1/edit', 'POST', server: ['HTTP_HX-Request' => 'true']));
+
+        self::assertStringStartsWith('/app_admin_accommodationbooking_edit', (string) $response->headers->get('HX-Redirect'));
+        self::assertSame('success', $controller->flashes[0]['type']);
+    }
+
+    public function testAPeriodWithoutABookingIsNotFound(): void
+    {
+        $controller = new TestableEditPeriodController(
+            $this->createStub(AccommodationBookingService::class),
+            $this->createStub(LoggerInterface::class),
+            $this->createStub(FormInterface::class),
+        );
+
+        $this->expectException(NotFoundHttpException::class);
+
+        $controller->index(
+            new AccommodationBookingPeriod(AccommodationBookingPeriodPosition::Leading, new \DateTimeImmutable('2026-07-01'), new \DateTimeImmutable('2026-07-02')),
+            Request::create('/admin/accommodation-booking-period/1/edit'),
+        );
+    }
+}
+
+final class TestableEditPeriodController extends EditPeriodController
+{
+    /** @var list<array{type: string, message: mixed}> */
+    public array $flashes = [];
+
+    public function __construct(
+        AccommodationBookingService $bookingService,
+        LoggerInterface $logger,
+        private readonly FormInterface $form,
+    ) {
+        parent::__construct($bookingService, $logger);
+    }
+
+    protected function createForm(string $type, mixed $data = null, array $options = []): FormInterface
+    {
+        return $this->form;
+    }
+
+    /**
+     * @param array<string, mixed> $parameters
+     */
+    protected function render(string $view, array $parameters = [], ?Response $response = null): Response
+    {
+        return new Response();
+    }
+
+    protected function addFlash(string $type, mixed $message): void
+    {
+        $this->flashes[] = ['type' => $type, 'message' => $message];
+    }
+
+    /**
+     * @param array<string, mixed> $parameters
+     */
+    protected function generateUrl(string $route, array $parameters = [], int $referenceType = 1): string
+    {
+        return '/'.$route.'?'.http_build_query($parameters);
+    }
+}

tests/Controller/Admin/AccommodationBooking/RemovePeriodControllerTest.php

@@ -0,0 +1,127 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Controller\Admin\AccommodationBooking;
+
+use App\Controller\Admin\AccommodationBooking\RemovePeriodController;
+use App\Entity\Groups\AccommodationBooking;
+use App\Entity\Groups\AccommodationBookingPeriod;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
+use App\Service\AccommodationBookingService;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+use Symfony\Component\Security\Core\Exception\AccessDeniedException;
+use Symfony\Component\Validator\ConstraintViolationList;
+
+class RemovePeriodControllerTest extends TestCase
+{
+    public function testGetAsksForConfirmation(): void
+    {
+        $bookingService = $this->createMock(AccommodationBookingService::class);
+        $bookingService->expects(self::never())->method('removePeriod');
+
+        $controller = new TestableRemovePeriodController($bookingService, $this->createStub(LoggerInterface::class));
+
+        $controller->index($this->period(), $this->request());
+
+        self::assertSame('admin/accommodation_booking/modal_remove_period.html.twig', $controller->renderedView);
+    }
+
+    public function testConfirmingRemovesThePeriodAndReturnsToTheEditForm(): void
+    {
+        $period = $this->period();
+
+        $bookingService = $this->createMock(AccommodationBookingService::class);
+        $bookingService->expects(self::once())->method('removePeriod')
+            ->with($period->getBooking(), $period)
+            ->willReturn(new ConstraintViolationList());
+
+        $controller = new TestableRemovePeriodController($bookingService, $this->createStub(LoggerInterface::class));
+
+        $response = $controller->index($period, $this->request('POST'));
+
+        self::assertStringStartsWith('/app_admin_accommodationbooking_edit', (string) $response->headers->get('HX-Redirect'));
+        self::assertSame('success', $controller->flashes[0]['type']);
+    }
+
+    public function testAnInvalidTokenRemovesNothing(): void
+    {
+        $bookingService = $this->createMock(AccommodationBookingService::class);
+        $bookingService->expects(self::never())->method('removePeriod');
+
+        $controller = new TestableRemovePeriodController($bookingService, $this->createStub(LoggerInterface::class));
+        $controller->tokenValid = false;
+
+        $this->expectException(AccessDeniedException::class);
+
+        $controller->index($this->period(), $this->request('POST'));
+    }
+
+    public function testAPeriodWithoutABookingIsNotFound(): void
+    {
+        $controller = new TestableRemovePeriodController($this->createStub(AccommodationBookingService::class), $this->createStub(LoggerInterface::class));
+
+        $this->expectException(NotFoundHttpException::class);
+
+        $controller->index(
+            new AccommodationBookingPeriod(AccommodationBookingPeriodPosition::Leading, new \DateTimeImmutable('2026-07-01'), new \DateTimeImmutable('2026-07-02')),
+            $this->request(),
+        );
+    }
+
+    private function period(): AccommodationBookingPeriod
+    {
+        $booking = (new AccommodationBooking())
+            ->setDateFrom(new \DateTimeImmutable('2026-07-01'))
+            ->setDateTo(new \DateTimeImmutable('2026-07-08'));
+
+        return $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Leading, 1);
+    }
+
+    private function request(string $method = 'GET'): Request
+    {
+        return Request::create('/admin/accommodation-booking-period/1/remove', $method, server: ['HTTP_HX-Request' => 'true']);
+    }
+}
+
+final class TestableRemovePeriodController extends RemovePeriodController
+{
+    public ?string $renderedView = null;
+
+    public bool $tokenValid = true;
+
+    /** @var list<array{type: string, message: mixed}> */
+    public array $flashes = [];
+
+    protected function isCsrfTokenValid(string $id, #[\SensitiveParameter] ?string $token): bool
+    {
+        return $this->tokenValid;
+    }
+
+    /**
+     * @param array<string, mixed> $parameters
+     */
+    protected function render(string $view, array $parameters = [], ?Response $response = null): Response
+    {
+        $this->renderedView = $view;
+
+        return new Response();
+    }
+
+    protected function addFlash(string $type, mixed $message): void
+    {
+        $this->flashes[] = ['type' => $type, 'message' => $message];
+    }
+
+    /**
+     * @param array<string, mixed> $parameters
+     */
+    protected function generateUrl(string $route, array $parameters = [], int $referenceType = 1): string
+    {
+        return '/'.$route.'?'.http_build_query($parameters);
+    }
+}

tests/Controller/Admin/AccommodationBooking/SplitPeriodControllerTest.php

@@ -0,0 +1,180 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Controller\Admin\AccommodationBooking;
+
+use App\Controller\Admin\AccommodationBooking\SplitPeriodController;
+use App\Entity\Groups\AccommodationBooking;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
+use App\Exception\ImplausibleBookingPriceException;
+use App\Service\AccommodationBookingService;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\Form\FormInterface;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Validator\ConstraintViolation;
+use Symfony\Component\Validator\ConstraintViolationList;
+
+/**
+ * Covers how the modal answers — the split itself is tested in AccommodationBookingServiceTest
+ * and AccommodationBookingTest.
+ */
+class SplitPeriodControllerTest extends TestCase
+{
+    public function testGetRendersTheModal(): void
+    {
+        $bookingService = $this->createMock(AccommodationBookingService::class);
+        $bookingService->expects(self::never())->method('splitOffPeriod');
+
+        $controller = $this->buildController($bookingService, $this->form(submitted: false));
+
+        $response = $controller->index(new AccommodationBooking(), AccommodationBookingPeriodPosition::Leading, $this->request());
+
+        self::assertSame(Response::HTTP_OK, $response->getStatusCode());
+        self::assertSame('admin/accommodation_booking/modal_period.html.twig', $controller->renderedView);
+    }
+
+    public function testASideThatWasAlreadySplitIsNotSplitAgain(): void
+    {
+        // The edit page only offers free sides; this is a page left open while the side was taken.
+        $booking = (new AccommodationBooking())
+            ->setDateFrom(new \DateTimeImmutable('2026-07-01'))
+            ->setDateTo(new \DateTimeImmutable('2026-07-08'));
+        $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Leading, 1);
+
+        $bookingService = $this->createMock(AccommodationBookingService::class);
+        $bookingService->expects(self::never())->method('splitOffPeriod');
+
+        $controller = $this->buildController($bookingService, $this->form(submitted: true));
+
+        $response = $controller->index($booking, AccommodationBookingPeriodPosition::Leading, $this->request('POST'));
+
+        self::assertTrue($response->headers->has('HX-Redirect'));
+        self::assertNull($controller->renderedView);
+        self::assertSame('error', $controller->flashes[0]['type']);
+    }
+
+    public function testAValidSplitSendsTheBrowserBackToTheEditForm(): void
+    {
+        $booking = new AccommodationBooking();
+
+        $bookingService = $this->createMock(AccommodationBookingService::class);
+        $bookingService->expects(self::once())->method('splitOffPeriod')
+            ->with($booking, AccommodationBookingPeriodPosition::Trailing)
+            ->willReturn(new ConstraintViolationList());
+
+        $controller = $this->buildController($bookingService, $this->form(submitted: true));
+
+        $response = $controller->index($booking, AccommodationBookingPeriodPosition::Trailing, $this->request('POST'));
+
+        self::assertSame(
+            '/app_admin_accommodationbooking_edit?r=%2Fadmin%2Faccommodation-booking%3Fpage%3D2',
+            $response->headers->get('HX-Redirect'),
+        );
+        self::assertSame('success', $controller->flashes[0]['type']);
+    }
+
+    public function testAViolationOfTheBookingIsReportedInTheModal(): void
+    {
+        $violations = new ConstraintViolationList([
+            new ConstraintViolation('Nach dem Abteilen der Zeiträume muss mindestens eine Nacht für die Gruppe bleiben.', null, [], null, 'dateTo', null),
+        ]);
+        $bookingService = $this->createStub(AccommodationBookingService::class);
+        $bookingService->method('splitOffPeriod')->willReturn($violations);
+
+        $controller = $this->buildController($bookingService, $this->form(submitted: true, expectsError: true));
+
+        $response = $controller->index(new AccommodationBooking(), AccommodationBookingPeriodPosition::Leading, $this->request('POST'));
+
+        self::assertFalse($response->headers->has('HX-Redirect'), 'the modal stays open on the error');
+        self::assertSame('admin/accommodation_booking/modal_period.html.twig', $controller->renderedView);
+        self::assertSame([], $controller->flashes);
+    }
+
+    public function testAnImplausibleTotalIsReportedInTheModal(): void
+    {
+        $bookingService = $this->createStub(AccommodationBookingService::class);
+        $bookingService->method('splitOffPeriod')
+            ->willThrowException(new ImplausibleBookingPriceException(AccommodationBooking::MAX_TOTAL_PRICE + 1, 40, 2));
+
+        $controller = $this->buildController($bookingService, $this->form(submitted: true, expectsError: true));
+
+        $response = $controller->index(new AccommodationBooking(), AccommodationBookingPeriodPosition::Leading, $this->request('POST'));
+
+        self::assertFalse($response->headers->has('HX-Redirect'));
+        self::assertSame('admin/accommodation_booking/modal_period.html.twig', $controller->renderedView);
+    }
+
+    private function request(string $method = 'GET'): Request
+    {
+        return Request::create(
+            '/admin/accommodation-booking/1/period/split/leading?r=%2Fadmin%2Faccommodation-booking%3Fpage%3D2',
+            $method,
+            server: ['HTTP_HX-Request' => 'true'],
+        );
+    }
+
+    private function form(bool $submitted, bool $expectsError = false): FormInterface
+    {
+        $form = $expectsError ? $this->createMock(FormInterface::class) : $this->createStub(FormInterface::class);
+        if ($form instanceof \PHPUnit\Framework\MockObject\MockObject) {
+            $form->expects(self::once())->method('addError');
+        }
+        $form->method('handleRequest')->willReturn($form);
+        $form->method('isSubmitted')->willReturn($submitted);
+        $form->method('isValid')->willReturn(true);
+
+        return $form;
+    }
+
+    private function buildController(AccommodationBookingService $bookingService, FormInterface $form): TestableSplitPeriodController
+    {
+        return new TestableSplitPeriodController($bookingService, $this->createStub(LoggerInterface::class), $form);
+    }
+}
+
+final class TestableSplitPeriodController extends SplitPeriodController
+{
+    public ?string $renderedView = null;
+
+    /** @var list<array{type: string, message: mixed}> */
+    public array $flashes = [];
+
+    public function __construct(
+        AccommodationBookingService $bookingService,
+        LoggerInterface $logger,
+        private readonly FormInterface $form,
+    ) {
+        parent::__construct($bookingService, $logger);
+    }
+
+    protected function createForm(string $type, mixed $data = null, array $options = []): FormInterface
+    {
+        return $this->form;
+    }
+
+    /**
+     * @param array<string, mixed> $parameters
+     */
+    protected function render(string $view, array $parameters = [], ?Response $response = null): Response
+    {
+        $this->renderedView = $view;
+
+        return new Response();
+    }
+
+    protected function addFlash(string $type, mixed $message): void
+    {
+        $this->flashes[] = ['type' => $type, 'message' => $message];
+    }
+
+    /**
+     * @param array<string, mixed> $parameters
+     */
+    protected function generateUrl(string $route, array $parameters = [], int $referenceType = 1): string
+    {
+        return '/'.$route.'?'.http_build_query($parameters);
+    }
+}

tests/Entity/Groups/AccommodationBookingTest.php

@@ -5,12 +5,16 @@ declare(strict_types=1);
 namespace App\Tests\Entity\Groups;
 
 use App\Entity\Groups\AccommodationBooking;
+use App\Entity\Groups\AccommodationBookingPeriod;
 use App\Entity\User;
 use App\Enum\Groups\AccommodationBookingOrigin;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
 use App\Enum\Groups\AccommodationBookingStatus;
 use App\Exception\ImplausibleBookingPriceException;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Validator\ConstraintViolationListInterface;
+use Symfony\Component\Validator\Validation;
 
 class AccommodationBookingTest extends TestCase
 {
@@ -209,6 +213,197 @@ class AccommodationBookingTest extends TestCase
         self::assertSame('Skiclub Nord', $booking->getGroupName());
     }
 
+    public function testACopyCarriesItsOwnSplitOffPeriods(): void
+    {
+        // The periods are part of the quote being varied, but editing them on the copy must
+        // not reach back into the original.
+        $booking = $this->confirmedBooking();
+        $booking->addPeriod((new AccommodationBookingPeriod(
+            AccommodationBookingPeriodPosition::Leading,
+            new \DateTimeImmutable('2026-03-01'),
+            new \DateTimeImmutable('2026-03-02'),
+        ))->setLines([['label' => 'Vorausteam', 'amount' => 30000]]));
+        $original = $booking->getPeriods()->first();
+
+        $copy = clone $booking;
+        $copied = $copy->getPeriods()->first();
+
+        self::assertCount(1, $copy->getPeriods());
+        self::assertNotSame($original, $copied);
+        self::assertSame($copy, $copied->getBooking());
+        self::assertNull($copied->getId());
+        self::assertSame($original->getLines(), $copied->getLines());
+        self::assertSame($booking, $original->getBooking());
+    }
+
+    public function testWithoutPeriodsTheMainPeriodIsTheWholeStay(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-08');
+
+        self::assertEquals(new \DateTimeImmutable('2026-03-01'), $booking->getMainDateFrom());
+        self::assertEquals(new \DateTimeImmutable('2026-03-08'), $booking->getMainDateTo());
+        self::assertSame(7, $booking->getMainNights());
+        self::assertSame(0, $booking->getPeriodsTotal());
+    }
+
+    public function testTheMainPeriodIsWhatRemainsBetweenTheSplitOffPeriods(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-08');
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Trailing, '2026-03-07', '2026-03-08', 2000));
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Leading, '2026-03-01', '2026-03-03', 3000));
+
+        self::assertEquals(new \DateTimeImmutable('2026-03-03'), $booking->getMainDateFrom());
+        self::assertEquals(new \DateTimeImmutable('2026-03-07'), $booking->getMainDateTo());
+        self::assertSame(4, $booking->getMainNights());
+        self::assertSame(7, $booking->getNights(), 'the stay itself is unchanged');
+        self::assertSame(5000, $booking->getPeriodsTotal());
+    }
+
+    public function testPeriodsThatTileTheEdgesOfTheStayAreValid(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-08');
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Leading, '2026-03-01', '2026-03-03', 0));
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Trailing, '2026-03-07', '2026-03-08', 0));
+
+        self::assertCount(0, $this->validate($booking));
+    }
+
+    public function testMovingTheArrivalAwayFromALeadingPeriodIsReportedOnTheArrival(): void
+    {
+        $booking = $this->stay('2026-03-02', '2026-03-08');
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Leading, '2026-03-01', '2026-03-03', 0));
+
+        $violations = $this->validate($booking);
+
+        self::assertCount(1, $violations);
+        self::assertSame('dateFrom', $violations[0]->getPropertyPath());
+    }
+
+    public function testASecondPeriodOnTheSameSideIsRefused(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-08');
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Leading, '2026-03-01', '2026-03-02', 0));
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Leading, '2026-03-01', '2026-03-02', 0));
+
+        self::assertCount(1, $this->validate($booking));
+    }
+
+    public function testMovingTheDepartureAwayFromATrailingPeriodIsReportedOnTheDeparture(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-09');
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Trailing, '2026-03-07', '2026-03-08', 0));
+
+        $violations = $this->validate($booking);
+
+        self::assertCount(1, $violations);
+        self::assertSame('dateTo', $violations[0]->getPropertyPath());
+    }
+
+    public function testTheGroupMustKeepAtLeastOneNight(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-03');
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Leading, '2026-03-01', '2026-03-02', 0));
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Trailing, '2026-03-02', '2026-03-03', 0));
+
+        $violations = $this->validate($booking);
+
+        self::assertCount(1, $violations);
+        self::assertSame('dateTo', $violations[0]->getPropertyPath());
+    }
+
+    public function testAPeriodWithoutANightIsRefused(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-08');
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Leading, '2026-03-01', '2026-03-01', 0));
+
+        self::assertCount(1, $this->validate($booking));
+    }
+
+    public function testSplittingOffAttachesThePeriodToItsEdgeOfTheStay(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-08');
+
+        $first = $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Leading, 2);
+        $last = $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Trailing, 1);
+
+        self::assertSame(['2026-03-01', '2026-03-03'], $this->range($first));
+        self::assertSame(['2026-03-07', '2026-03-08'], $this->range($last));
+        self::assertSame(4, $booking->getMainNights());
+        self::assertCount(0, $this->validate($booking));
+    }
+
+    public function testEachSideCanOnlyBeSplitOnce(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-08');
+        $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Leading, 1);
+
+        self::assertFalse($booking->canSplitOffPeriod(AccommodationBookingPeriodPosition::Leading));
+        self::assertTrue($booking->canSplitOffPeriod(AccommodationBookingPeriodPosition::Trailing));
+
+        $this->expectException(\LogicException::class);
+        $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Leading, 1);
+    }
+
+    public function testResizingKeepsAPeriodAtItsEdge(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-10');
+        $period = $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Trailing, 1);
+
+        $booking->resizePeriod($period, 3);
+
+        self::assertSame(['2026-03-07', '2026-03-10'], $this->range($period));
+        self::assertSame(6, $booking->getMainNights());
+    }
+
+    public function testRemovingAPeriodGivesItsNightsBackAndFreesTheSide(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-08');
+        $period = $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Leading, 2);
+
+        $booking->removePeriod($period);
+
+        self::assertNull($period->getBooking());
+        self::assertSame(7, $booking->getMainNights());
+        self::assertTrue($booking->canSplitOffPeriod(AccommodationBookingPeriodPosition::Leading));
+    }
+
+    public function testGrowingAPeriodIntoTheLastNightOfTheGroupIsRefused(): void
+    {
+        $booking = $this->stay('2026-03-01', '2026-03-04');
+        $period = $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Leading, 1);
+
+        $booking->resizePeriod($period, 3);
+
+        self::assertCount(1, $this->validate($booking));
+    }
+
+    /** @return array{string, string} */
+    private function range(AccommodationBookingPeriod $period): array
+    {
+        return [$period->getDateFrom()->format('Y-m-d'), $period->getDateTo()->format('Y-m-d')];
+    }
+
+    private function stay(string $from, string $to): AccommodationBooking
+    {
+        return (new AccommodationBooking())
+            ->setDateFrom(new \DateTimeImmutable($from))
+            ->setDateTo(new \DateTimeImmutable($to));
+    }
+
+    private function period(AccommodationBookingPeriodPosition $position, string $from, string $to, int $amount): AccommodationBookingPeriod
+    {
+        return (new AccommodationBookingPeriod($position, new \DateTimeImmutable($from), new \DateTimeImmutable($to)))
+            ->setLines([['label' => 'Vorausteam', 'amount' => $amount]]);
+    }
+
+    private function validate(AccommodationBooking $booking): ConstraintViolationListInterface
+    {
+        return Validation::createValidatorBuilder()
+            ->enableAttributeMapping()
+            ->getValidator()
+            ->validate($booking);
+    }
+
     /**
      * A record that has been all the way through the lifecycle, so a copy of it has the most
      * to reset.

tests/Form/Model/AccommodationBookingPeriodDtoTest.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Form\Model;
+
+use App\Entity\Groups\AccommodationBookingPeriod;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
+use App\Form\Model\AccommodationBookingPeriodDto;
+use App\Form\Model\AccommodationBookingPeriodLineDto;
+use PHPUnit\Framework\TestCase;
+
+class AccommodationBookingPeriodDtoTest extends TestCase
+{
+    public function testTheEditModalStartsFromWhatThePeriodHolds(): void
+    {
+        $period = (new AccommodationBookingPeriod(
+            AccommodationBookingPeriodPosition::Leading,
+            new \DateTimeImmutable('2026-07-01'),
+            new \DateTimeImmutable('2026-07-03'),
+        ))
+            ->setLabel('Vorausteam')
+            ->setLines([['label' => 'Übernachtung', 'amount' => 25000]]);
+
+        $dto = AccommodationBookingPeriodDto::fromPeriod($period);
+
+        self::assertSame('Vorausteam', $dto->label);
+        self::assertSame(2, $dto->nights);
+        self::assertSame([['label' => 'Übernachtung', 'amount' => 25000]], $dto->linesSnapshot());
+    }
+
+    public function testTheLinesAreStoredAsAListWhateverKeysTheFormSubmitted(): void
+    {
+        // A collection form keeps the indexes of the rows it was sent, so after a removed row
+        // the keys have gaps — the JSON column must still get a list, not an object.
+        $dto = new AccommodationBookingPeriodDto(1, [
+            2 => new AccommodationBookingPeriodLineDto('Übernachtung', 25000),
+            5 => new AccommodationBookingPeriodLineDto('Verpflegung', 6000),
+        ]);
+
+        self::assertSame([
+            ['label' => 'Übernachtung', 'amount' => 25000],
+            ['label' => 'Verpflegung', 'amount' => 6000],
+        ], $dto->linesSnapshot());
+    }
+}

tests/Service/AccommodationBookingBreakdownCalculatorTest.php

@@ -6,6 +6,9 @@ namespace App\Tests\Service;
 
 use App\Entity\Groups\Accommodation;
 use App\Entity\Groups\AccommodationBooking;
+use App\Entity\Groups\AccommodationBookingPeriod;
+use App\Entity\Groups\AccommodationPrice;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
 use App\Repository\Groups\AccommodationPriceRepository;
 use App\Service\AccommodationBookingBreakdownCalculator;
 use App\Service\GroupsPriceCalculator;
@@ -190,6 +193,124 @@ class AccommodationBookingBreakdownCalculatorTest extends TestCase
         self::assertArrayNotHasKey('discountedTotal', $breakdown);
     }
 
+    public function testAVersion1SnapshotReadsAsABookingWithoutPeriods(): void
+    {
+        $booking = new AccommodationBooking();
+        $booking->setPriceSnapshot($this->breakdown(), 12345, 'CHF', 1);
+
+        $breakdown = $this->createCalculator()->compute($booking);
+
+        self::assertSame([], $breakdown['periods']);
+        self::assertSame(0, $breakdown['periodsTotal']);
+        self::assertSame(12345, $breakdown['discountedTotal']);
+    }
+
+    public function testWithoutPeriodsTheCatalogPricesTheWholeStay(): void
+    {
+        // Regression guard: a booking nobody split is priced exactly as before periods existed.
+        $booking = $this->stay();
+
+        $breakdown = $this->createCalculator($this->priceRepository())->computeCurrent($booking);
+
+        self::assertSame(7, $breakdown['nights']);
+        self::assertSame(7 * 100_00, $breakdown['basePrice']);
+        self::assertSame(7 * 100_00, $breakdown['total']);
+        self::assertSame([], $breakdown['periods']);
+        self::assertSame(0, $breakdown['periodsTotal']);
+    }
+
+    public function testTheCatalogPricesOnlyTheMainPeriodAndThePeriodLinesAreAddedOnTop(): void
+    {
+        $booking = $this->stay();
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Trailing, '2026-07-07', '2026-07-08', [['label' => 'Abbau', 'amount' => 100_00]]));
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Leading, '2026-07-01', '2026-07-02', [
+            ['label' => 'Übernachtung', 'amount' => 250_00],
+            ['label' => 'Verpflegung', 'amount' => 50_00],
+        ])->setLabel('Vorausteam'));
+
+        $breakdown = $this->createCalculator($this->priceRepository())->computeCurrent($booking);
+
+        self::assertSame(5, $breakdown['nights']);
+        self::assertSame(5 * 100_00, $breakdown['basePrice']);
+        self::assertSame(400_00, $breakdown['periodsTotal']);
+        self::assertSame(5 * 100_00 + 400_00, $breakdown['total']);
+        self::assertSame([
+            [
+                'position' => 'leading',
+                'label' => 'Vorausteam',
+                'dateFrom' => '2026-07-01',
+                'dateTo' => '2026-07-02',
+                'nights' => 1,
+                'lines' => [
+                    ['label' => 'Übernachtung', 'amount' => 250_00],
+                    ['label' => 'Verpflegung', 'amount' => 50_00],
+                ],
+                'total' => 300_00,
+            ],
+            [
+                'position' => 'trailing',
+                'label' => null,
+                'dateFrom' => '2026-07-07',
+                'dateTo' => '2026-07-08',
+                'nights' => 1,
+                'lines' => [['label' => 'Abbau', 'amount' => 100_00]],
+                'total' => 100_00,
+            ],
+        ], $breakdown['periods']);
+    }
+
+    public function testOnlyTheFixedDiscountReachesThePeriodLines(): void
+    {
+        // The section discounts belong to the catalog-priced main period; the fixed discount
+        // is taken off the grand total, so it may exceed what the main period alone costs.
+        $booking = $this->stay();
+        $booking->addPeriod($this->period(AccommodationBookingPeriodPosition::Leading, '2026-07-01', '2026-07-02', [['label' => 'Vorausteam', 'amount' => 1000_00]]));
+        $booking->setAccommodationDiscount(10);
+        $booking->setTotalDiscountAmount(900_00);
+        $booking->setTotalDiscountLabel('Sonderpreis');
+        $calculator = $this->createCalculator($this->priceRepository());
+
+        $breakdown = $calculator->withDiscounts($booking, $calculator->computeCurrent($booking));
+
+        self::assertSame([['label' => 'Rabatt Unterkunft', 'percent' => 10, 'amount' => 60_00]], $breakdown['discounts']);
+        self::assertSame(600_00 + 1000_00 - 60_00, $breakdown['discountSubtotal']);
+        self::assertSame(600_00 + 1000_00 - 60_00 - 900_00, $breakdown['discountedTotal']);
+    }
+
+    private function stay(): AccommodationBooking
+    {
+        $booking = new AccommodationBooking();
+        $booking->setAccommodation((new Accommodation())->setCalendarCode('HOTEL')->setCurrency('EUR'));
+        $booking->setDateFrom(new \DateTimeImmutable('2026-07-01'));
+        $booking->setDateTo(new \DateTimeImmutable('2026-07-08'));
+        $booking->setPaxCount(20);
+
+        return $booking;
+    }
+
+    /** @param list<array{label: string, amount: int}> $lines */
+    private function period(AccommodationBookingPeriodPosition $position, string $from, string $to, array $lines): AccommodationBookingPeriod
+    {
+        return (new AccommodationBookingPeriod($position, new \DateTimeImmutable($from), new \DateTimeImmutable($to)))
+            ->setLines($lines);
+    }
+
+    private function priceRepository(): AccommodationPriceRepository
+    {
+        $price = (new AccommodationPrice())
+            ->setDateFrom(new \DateTimeImmutable('2026-06-01'))
+            ->setDateTo(new \DateTimeImmutable('2026-08-31'))
+            ->setIncludedPax(20)
+            ->setPricePerNight(100_00)
+            ->setPriceAdditionalPerson(10_00)
+            ->setMinNights(1);
+
+        $priceRepository = $this->createStub(AccommodationPriceRepository::class);
+        $priceRepository->method('findByHotelCodeAndDateRange')->willReturn([$price]);
+
+        return $priceRepository;
+    }
+
     /**
      * @return array<string, mixed>
      */

tests/Service/AccommodationBookingPdfGeneratorTest.php

@@ -6,6 +6,7 @@ namespace App\Tests\Service;
 
 use App\Entity\Groups\Accommodation;
 use App\Entity\Groups\AccommodationBooking;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
 use App\Service\AccommodationBookingBreakdownCalculator;
 use App\Service\AccommodationBookingPdfGenerator;
 use PHPUnit\Framework\TestCase;
@@ -27,6 +28,37 @@ class AccommodationBookingPdfGeneratorTest extends TestCase
         self::assertSame(1, $this->pageCount($pdf));
     }
 
+    public function testADocumentWithSplitOffPeriodsStillFitsOnASingleA4Page(): void
+    {
+        $booking = $this->booking();
+        $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Leading, 1)->setLabel('Vorausteam')->setLines([
+            ['label' => 'Vorausteam Übernachtung', 'amount' => 25000],
+            ['label' => 'Vorausteam Verpflegung', 'amount' => 6000],
+        ]);
+        $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Trailing, 1)->setLines([
+            ['label' => 'Abbau', 'amount' => 10000],
+        ]);
+
+        $breakdown = [
+            ...$this->breakdown(),
+            'nights' => 3,
+            'periods' => [
+                ['position' => 'leading', 'label' => 'Vorausteam', 'dateFrom' => '2026-07-06', 'dateTo' => '2026-07-07', 'nights' => 1, 'lines' => [
+                    ['label' => 'Vorausteam Übernachtung', 'amount' => 25000],
+                    ['label' => 'Vorausteam Verpflegung', 'amount' => 6000],
+                ], 'total' => 31000],
+                ['position' => 'trailing', 'dateFrom' => '2026-07-10', 'dateTo' => '2026-07-11', 'nights' => 1, 'lines' => [
+                    ['label' => 'Abbau', 'amount' => 10000],
+                ], 'total' => 10000],
+            ],
+            'periodsTotal' => 41000,
+        ];
+
+        $pdf = $this->createGenerator($breakdown)->render($booking);
+
+        self::assertSame(1, $this->pageCount($pdf));
+    }
+
     public function testTheDownloadIsAnAttachmentNamedAfterArrivalDateAndHotel(): void
     {
         $response = $this->createGenerator($this->breakdown())->createDownloadResponse($this->booking());
@@ -122,6 +154,8 @@ class AccommodationBookingPdfGeneratorTest extends TestCase
             'serviceDetails' => [['label' => 'Bettwäsche', 'price' => 28800]],
             'servicesPrice' => 28800,
             'runningCosts' => 16000,
+            'periods' => [],
+            'periodsTotal' => 0,
             'total' => 844800,
             'currency' => 'EUR',
             'discounts' => [['label' => 'Unterkunft', 'percent' => 5, 'amount' => 16000]],

tests/Service/AccommodationBookingServiceTest.php

@@ -10,10 +10,13 @@ use App\Entity\Groups\Accommodation;
 use App\Entity\Groups\AccommodationBooking;
 use App\Entity\Groups\AccommodationPrice;
 use App\Enum\Groups\AccommodationBookingOrigin;
+use App\Enum\Groups\AccommodationBookingPeriodPosition;
 use App\Enum\Groups\AccommodationBookingStatus;
 use App\Enum\Groups\AdditionalServiceType;
 use App\Exception\ImplausibleBookingPriceException;
 use App\Form\Model\AccommodationBookingDto;
+use App\Form\Model\AccommodationBookingPeriodDto;
+use App\Form\Model\AccommodationBookingPeriodLineDto;
 use App\Model\AccommodationBookingQueryParams;
 use App\Repository\Groups\AccommodationPriceRepository;
 use App\Repository\Groups\AccommodationRepository;
@@ -951,7 +954,86 @@ class AccommodationBookingServiceTest extends TestCase
         self::assertSame($breakdown, $booking->getPriceBreakdown(), 'the derived keys must not be persisted');
         self::assertSame(10895, $booking->getTotalPrice());
         self::assertSame('CHF', $booking->getPricingCurrency());
-        self::assertSame(1, $booking->getPricingVersion());
+        self::assertSame(2, $booking->getPricingVersion());
+    }
+
+    public function testSplittingOffAPeriodRepricesAndWritesTheBooking(): void
+    {
+        $booking = $this->periodBooking();
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager->expects(self::once())->method('flush');
+        $breakdownCalculator = $this->createMock(AccommodationBookingBreakdownCalculator::class);
+        $breakdownCalculator->expects(self::once())->method('computeCurrent')->with($booking)->willReturn(null);
+
+        $service = $this->createServiceWithAccommodation(entityManager: $entityManager, breakdownCalculator: $breakdownCalculator);
+        $violations = $service->splitOffPeriod(
+            $booking,
+            AccommodationBookingPeriodPosition::Leading,
+            new AccommodationBookingPeriodDto(1, [3 => new AccommodationBookingPeriodLineDto('Übernachtung', 30000)], 'Vorausteam'),
+        );
+
+        self::assertCount(0, $violations);
+        self::assertSame('Vorausteam', $booking->getLeadingPeriod()?->getLabel());
+        self::assertSame([['label' => 'Übernachtung', 'amount' => 30000]], $booking->getLeadingPeriod()?->getLines());
+        self::assertSame(6, $booking->getMainNights());
+    }
+
+    public function testASplitThatLeavesTheGroupNoNightIsNeitherPricedNorWritten(): void
+    {
+        $booking = $this->periodBooking();
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager->expects(self::never())->method('flush');
+        $breakdownCalculator = $this->createMock(AccommodationBookingBreakdownCalculator::class);
+        $breakdownCalculator->expects(self::never())->method('computeCurrent');
+
+        $service = $this->createServiceWithAccommodation(entityManager: $entityManager, breakdownCalculator: $breakdownCalculator);
+        $violations = $service->splitOffPeriod($booking, AccommodationBookingPeriodPosition::Trailing, new AccommodationBookingPeriodDto(7));
+
+        self::assertCount(1, $violations);
+    }
+
+    public function testUpdatingAPeriodChangesItsLengthAndLines(): void
+    {
+        $booking = $this->periodBooking();
+        $period = $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Trailing, 1);
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager->expects(self::once())->method('flush');
+
+        $service = $this->createServiceWithAccommodation(entityManager: $entityManager);
+        $violations = $service->updatePeriod($booking, $period, new AccommodationBookingPeriodDto(2, [new AccommodationBookingPeriodLineDto('Abbau', 5000)]));
+
+        self::assertCount(0, $violations);
+        self::assertSame(2, $period->getNights());
+        self::assertSame([['label' => 'Abbau', 'amount' => 5000]], $period->getLines());
+        self::assertSame(5, $booking->getMainNights());
+    }
+
+    public function testRemovingAPeriodGivesItsNightsBackToTheGroup(): void
+    {
+        $booking = $this->periodBooking();
+        $period = $booking->splitOffPeriod(AccommodationBookingPeriodPosition::Leading, 2);
+
+        $entityManager = $this->createMock(EntityManagerInterface::class);
+        $entityManager->expects(self::once())->method('flush');
+
+        $service = $this->createServiceWithAccommodation(entityManager: $entityManager);
+        $violations = $service->removePeriod($booking, $period);
+
+        self::assertCount(0, $violations);
+        self::assertTrue($booking->getPeriods()->isEmpty());
+        self::assertSame(7, $booking->getMainNights());
+    }
+
+    private function periodBooking(): AccommodationBooking
+    {
+        return (new AccommodationBooking())
+            ->setAccommodation((new Accommodation())->setCalendarCode('HOTEL'))
+            ->setDateFrom(new \DateTimeImmutable('2026-07-01'))
+            ->setDateTo(new \DateTimeImmutable('2026-07-08'))
+            ->setPaxCount(20);
     }
 
     public function testChangeAccommodationSwapsTheHouseAndDropsTheBookedServices(): void

tests/Service/GroupsPriceCalculatorTest.php

@@ -48,6 +48,97 @@ class GroupsPriceCalculatorTest extends TestCase
         self::assertSame(50, $result['undersubscriptionThreshold']);
     }
 
+    public function testTheShortTermSurchargeIsJudgedOnTheWholeStay(): void
+    {
+        // Three nights priced for the group, but one night split off a four-night stay: the
+        // stay is not short-term, so the three nights must not pick up the 10 % surcharge.
+        $price = $this->price('2026-06-01', '2026-08-31', 20);
+
+        $split = $this->calculateMain('2026-07-02', '2026-07-05', '2026-07-01', 4, [$price]);
+        $unsplit = $this->calculateMain('2026-07-02', '2026-07-05', '2026-07-02', 3, [$price]);
+
+        self::assertSame(0, $split['shortTermSurcharge']);
+        self::assertSame(3, $split['nights']);
+        self::assertSame((int) round(($unsplit['basePrice'] + $unsplit['additionalPersonsPrice']) * 10 / 100), $unsplit['shortTermSurcharge']);
+    }
+
+    public function testTheShortTermSurchargeOfAShortStayIsChargedOnThePricedNightsOnly(): void
+    {
+        // A three-night stay with one night split off: 10 % on the two nights the group pays
+        // for, not 20 % for a two-night stay and not on the split-off night's lines.
+        $price = $this->price('2026-06-01', '2026-08-31', 20);
+
+        $result = $this->calculateMain('2026-07-02', '2026-07-04', '2026-07-01', 3, [$price]);
+
+        self::assertSame(2 * 100_00, $result['basePrice']);
+        self::assertSame((int) round(($result['basePrice'] + $result['additionalPersonsPrice']) * 10 / 100), $result['shortTermSurcharge']);
+    }
+
+    public function testTheIncludedPaxFloorComesFromTheStaysFirstNight(): void
+    {
+        // The stay starts in a price period with a floor of 30; the main group arrives a day
+        // later, in one with a floor of 50. Splitting the first night off must not raise the
+        // floor the 20 people are billed at.
+        $prices = [
+            $this->price('2026-06-01', '2026-07-01', 30),
+            $this->price('2026-07-02', '2026-08-31', 50),
+        ];
+
+        $result = $this->calculateMain('2026-07-02', '2026-07-08', '2026-07-01', 7, $prices, paxCount: 20, boardServicePrice: 1500);
+
+        self::assertSame(30, $result['includedPax']);
+        self::assertSame(30, $result['effectivePax']);
+        self::assertSame(1500 * 30 * 6, $result['boardPrice']);
+    }
+
+    /**
+     * @param list<AccommodationPrice> $prices
+     *
+     * @return array<string, mixed>
+     */
+    private function calculateMain(string $from, string $to, string $stayFrom, int $stayNights, array $prices, int $paxCount = 20, ?int $boardServicePrice = null): array
+    {
+        $dateFrom = new \DateTimeImmutable($from);
+        $dateTo = new \DateTimeImmutable($to);
+
+        return $this->calculator()->calculateFromSnapshots(
+            $paxCount,
+            0,
+            $dateFrom->diff($dateTo)->days,
+            $dateFrom,
+            $dateTo,
+            new \DateTimeImmutable($stayFrom),
+            $stayNights,
+            $prices,
+            $boardServicePrice,
+            [],
+            'EUR',
+        );
+    }
+
+    private function price(string $from, string $to, int $includedPax): AccommodationPrice
+    {
+        return (new AccommodationPrice())
+            ->setDateFrom(new \DateTimeImmutable($from))
+            ->setDateTo(new \DateTimeImmutable($to))
+            ->setIncludedPax($includedPax)
+            ->setPricePerNight(100_00)
+            ->setPriceAdditionalPerson(10_00)
+            ->setMinNights(1);
+    }
+
+    private function calculator(): GroupsPriceCalculator
+    {
+        return new GroupsPriceCalculator(new PriceTimelineBuilder(), [
+            'runningCostsEur' => 0,
+            'runningCostsChf' => 0,
+            'undersubscription30Eur' => 5.0,
+            'undersubscription30Chf' => 6.0,
+            'undersubscription40Eur' => 2.5,
+            'undersubscription40Chf' => 3.0,
+        ]);
+    }
+
     /**
      * @return array<string, mixed>
      */
@@ -64,21 +155,14 @@ class GroupsPriceCalculatorTest extends TestCase
             ->setPriceAdditionalPerson(10_00)
             ->setMinNights(1);
 
-        $calculator = new GroupsPriceCalculator(new PriceTimelineBuilder(), [
-            'runningCostsEur' => 0,
-            'runningCostsChf' => 0,
-            'undersubscription30Eur' => 5.0,
-            'undersubscription30Chf' => 6.0,
-            'undersubscription40Eur' => 2.5,
-            'undersubscription40Chf' => 3.0,
-        ]);
-
-        return $calculator->calculateFromSnapshots(
+        return $this->calculator()->calculateFromSnapshots(
             $paxCount,
             0,
             self::NIGHTS,
             $dateFrom,
             $dateTo,
+            $dateFrom,
+            self::NIGHTS,
             [$price],
             $boardServicePrice,
             [],