diff --git a/assets/controllers/birthday_controller.js b/assets/controllers/birthday_controller.js
new file mode 100644
index 0000000..f9cc334
--- /dev/null
+++ b/assets/controllers/birthday_controller.js
@@ -0,0 +1,59 @@
+import { Controller } from '@hotwired/stimulus'
+
+/**
+ * Monitors birthday input fields (day, month, year) and dispatches a custom event
+ * only when all three fields are filled with valid values.
+ *
+ * This prevents premature HTMX refreshes when users are still entering the date,
+ * improving UX by waiting until the complete date is entered.
+ */
+export default class extends Controller {
+    static targets = ['day', 'month', 'year']
+
+    /**
+     * Checks if all birthday fields are filled and dispatches a completion event.
+     *
+     * Called on input/change events from the day, month, and year fields.
+     * Only dispatches the 'birthday:complete' event when all three fields
+     * contain valid values that could form a complete date.
+     */
+    check() {
+        const day = this.dayTarget.value.trim()
+        const month = this.monthTarget.value.trim()
+        const year = this.yearTarget.value.trim()
+
+        if (false === this.isComplete(day, month, year)) {
+            return
+        }
+
+        this.element.dispatchEvent(new CustomEvent('birthday:complete', { bubbles: true }))
+    }
+
+    /**
+     * Validates that all date components are filled with plausible values.
+     *
+     * @param {string} day   The day value
+     * @param {string} month The month value
+     * @param {string} year  The year value
+     *
+     * @returns {boolean} True if all fields contain complete values
+     */
+    isComplete(day, month, year) {
+        // Day: 1-2 digits
+        if (0 === day.length || day.length > 2) {
+            return false
+        }
+
+        // Month: 1-2 digits
+        if (0 === month.length || month.length > 2) {
+            return false
+        }
+
+        // Year: exactly 4 digits for a complete year
+        if (4 !== year.length) {
+            return false
+        }
+
+        return true
+    }
+}
diff --git a/templates/forms.html.twig b/templates/forms.html.twig
index 464cfb7..5f9da02 100644
--- a/templates/forms.html.twig
+++ b/templates/forms.html.twig
@@ -253,8 +253,24 @@
         'year': 'Jahr'
     } -%}
     {%- set field_order = ['day', 'month', 'year'] -%}
+
+    {# Check if HTMX attributes are present - if so, use birthday controller for deferred triggering #}
+    {%- set has_htmx = attr['hx-trigger'] is defined -%}
+    {%- set htmx_attrs = {} -%}
+    {%- if has_htmx -%}
+        {# Extract HTMX attributes and replace trigger with custom event #}
+        {%- set htmx_attrs = {
+            'hx-trigger': 'birthday:complete',
+            'hx-post': attr['hx-post']|default(''),
+            'hx-target': attr['hx-target']|default('#main-content'),
+            'hx-swap': attr['hx-swap']|default('innerHTML')
+        } -%}
+        {# Remove HTMX attrs from main attr to avoid duplication #}
+        {%- set attr = attr|filter((v, k) => k not in ['hx-trigger', 'hx-post', 'hx-target', 'hx-swap']) -%}
+    {%- endif -%}
+
     {%- set attr = attr|merge({'class': (attr.class|default('') ~ ' flex items-center space-x-2')|trim}) -%}
-    <div {{ block('widget_container_attributes') }}>
+    <div {{ block('widget_container_attributes') }}{% if has_htmx %} {{ stimulus_controller('birthday') }}{% for key, value in htmx_attrs %} {{ key }}="{{ value }}"{% endfor %}{% endif %}>
         {%- for field_name in field_order -%}
             {%- set child = form[field_name] -%}
             {%- set child_attr = child.vars.attr|default({}) -%}
@@ -262,6 +278,12 @@
                 'placeholder': placeholders[field_name],
                 'class': (child_attr.class|default('') ~ ' form-field')|trim
             }) -%}
+            {%- if has_htmx -%}
+                {%- set child_attr = child_attr|merge({
+                    'data-birthday-target': field_name,
+                    'data-action': 'change->birthday#check'
+                }) -%}
+            {%- endif -%}
 
             {{- form_widget(child, {'attr': child_attr}) -}}
             {% if not loop.last %}