diff --git a/templates/includes/macros.html.tera b/templates/includes/macros.html.tera
index 5007909..80d1413 100644
--- a/templates/includes/macros.html.tera
+++ b/templates/includes/macros.html.tera
@@ -24,9 +24,9 @@
     <div class="h-8"></div>
 {% endmacro header %}
 
-{% macro input(label, name, type, required=false, class='rounded-md', value='') %}
+{% macro input(label, name, type, required=false, class='rounded-md', value='', min='') %}
   <label for="{{ name }}" class="sr-only">{{ label }}</label>
-  <input id="{{ name }}" name="{{ name }}" type="{{ type }}" {% if required %} required {% endif %} value="{{ value }}" class="input {{ class }}" placeholder="{{ label }}">
+  <input id="{{ name }}" name="{{ name }}" type="{{ type }}" {% if required %} required {% endif %} value="{{ value }}" class="input {{ class }}" placeholder="{{ label }}" {% if min %} min="{{ min }}" {% endif %}>
 {% endmacro input %}
 
 {% macro checkbox(label, name, id='', checked=false) %}
diff --git a/templates/index.html.tera b/templates/index.html.tera
index 41fa00e..f9a859e 100644
--- a/templates/index.html.tera
+++ b/templates/index.html.tera
@@ -193,7 +193,7 @@
             <div class="bg-gray-100 p-3 mt-4 rounded-md">
               <h3 class="text-primary-950 font-bold uppercase tracking-wide mb-2">Ausfahrt bearbeiten</h3>
               <form action="/cox/trip/{{ trip.id }}" method="post" class="grid gap-3">
-                {{ macros::input(label='Anzahl Ruderer', name='max_people', type='number', required=true, value=trip.max_people) }}
+                {{ macros::input(label='Anzahl Ruderer', name='max_people', type='number', required=true, value=trip.max_people, min='0') }}
                 {{ macros::input(label='Anmerkungen', name='notes', type='input', value=trip.notes) }}
                 <input value="Bearbeiten" class="btn btn-primary" type="submit" />
               </form>
@@ -277,8 +277,8 @@
 <div class="hidden">
   <form action="/cox/trip" method="post" class="grid gap-3" id="sidebarForm">
     <input class="day-js" type="hidden" name="day" value="" />
-    {{ macros::input(label='Startzeit (zB "10:00")', name='planned_starting_time', type='input', required=true) }}
-    {{ macros::input(label='Anzahl Ruderer', name='max_people', type='number', required=true) }}
+    {{ macros::input(label='Startzeit (zB "10:00")', name='planned_starting_time', type='time', required=true) }}
+    {{ macros::input(label='Anzahl Ruderer', name='max_people', type='number', required=true, min='0') }}
     {{ macros::input(label='Anmerkungen', name='notes', type='input') }}
     <input value="Erstellen" class="w-full btn btn-primary" type="submit" />
   </form>
@@ -290,9 +290,9 @@
   <form action="/admin/planned-event" method="post" class="grid gap-3" id="addEventForm">
     <input class="day-js" type="hidden" name="day" value="" />
     {{ macros::input(label='Titel (z.B. Firmenrudern)', name='name', type='input', required=true) }}
-    {{ macros::input(label='Startzeit', name='planned_starting_time', type='input', required=true) }}
-    {{ macros::input(label='Anzahl Steuerleute', name='planned_amount_cox', type='number', required=true) }}
-    {{ macros::input(label='Anzahl Ruderer', name='max_people', type='number', required=true) }}
+    {{ macros::input(label='Startzeit', name='planned_starting_time', type='time', required=true) }}
+    {{ macros::input(label='Anzahl Steuerleute', name='planned_amount_cox', type='number', required=true, min='0') }}
+    {{ macros::input(label='Anzahl Ruderer', name='max_people', type='number', required=true, min='0') }}
     {{ macros::checkbox(label='Gäste erlauben', name='max_allow_guestspeople') }}
     {{ macros::input(label='Anmerkungen', name='notes', type='input') }}
     <input value="Erstellen" class="w-full btn btn-primary" type="submit" />