diff --git a/src/views/admin/create-hunt.ejs b/src/views/admin/create-hunt.ejs
index 91c9daf..7d09290 100644
--- a/src/views/admin/create-hunt.ejs
+++ b/src/views/admin/create-hunt.ejs
@@ -35,8 +35,9 @@
       </div>
 
       <div class="form-group">
-        <label for="start_date">Start Date (optional)</label>
-        <input type="datetime-local" id="start_date" name="start_date" class="form-control">
+        <label for="start_date_picker">Start Date (optional)</label>
+        <input type="datetime-local" id="start_date_picker" class="form-control">
+        <input type="hidden" id="start_date" name="start_date">
         <div class="form-hint">When the hunt becomes active. Leave blank to start immediately.</div>
       </div>
 
@@ -47,8 +48,9 @@
       </div>
 
       <div class="form-group">
-        <label for="expiry_date">Expiry Date (optional)</label>
-        <input type="datetime-local" id="expiry_date" name="expiry_date" class="form-control">
+        <label for="expiry_date_picker">Expiry Date (optional)</label>
+        <input type="datetime-local" id="expiry_date_picker" class="form-control">
+        <input type="hidden" id="expiry_date" name="expiry_date">
         <div class="form-hint">Leave blank for no expiry.</div>
       </div>
 
@@ -58,13 +60,12 @@
 </div>
 
 <script>
-// Convert datetime-local (user's local time) to UTC ISO before submit
 document.querySelector('form').addEventListener('submit', function() {
-  ['start_date', 'expiry_date'].forEach(function(name) {
-    var input = document.getElementById(name);
-    if (input && input.value) {
-      var d = new Date(input.value);
-      if (!isNaN(d)) input.value = d.toISOString();
+  [['start_date_picker', 'start_date'], ['expiry_date_picker', 'expiry_date']].forEach(function(pair) {
+    var picker = document.getElementById(pair[0]);
+    var hidden = document.getElementById(pair[1]);
+    if (picker.value) {
+      hidden.value = new Date(picker.value).toISOString();
     }
   });
 });
diff --git a/src/views/admin/edit-hunt.ejs b/src/views/admin/edit-hunt.ejs
index a558261..213ca10 100644
--- a/src/views/admin/edit-hunt.ejs
+++ b/src/views/admin/edit-hunt.ejs
@@ -31,8 +31,9 @@
 
       <div class="form-group">
         <label for="start_date">Start Date (optional)</label>
-        <input type="datetime-local" id="start_date" name="start_date" class="form-control"
+        <input type="datetime-local" id="start_date_picker" class="form-control"
                data-utc="<%= hunt.start_date || '' %>">
+        <input type="hidden" id="start_date" name="start_date">
         <div class="form-hint">When the hunt becomes active. Leave blank to start immediately.</div>
       </div>
 
@@ -44,8 +45,9 @@
 
       <div class="form-group">
         <label for="expiry_date">Expiry Date (optional)</label>
-        <input type="datetime-local" id="expiry_date" name="expiry_date" class="form-control"
+        <input type="datetime-local" id="expiry_date_picker" class="form-control"
                data-utc="<%= hunt.expiry_date || '' %>">
+        <input type="hidden" id="expiry_date" name="expiry_date">
         <div class="form-hint">Leave blank for no expiry.</div>
       </div>
 
@@ -54,7 +56,7 @@
   </div>
 
 <script>
-// Populate datetime-local inputs from stored UTC values (convert to local)
+// Populate datetime-local pickers from stored UTC values (convert to local)
 document.querySelectorAll('input[data-utc]').forEach(function(input) {
   var utc = input.dataset.utc;
   if (utc) {
@@ -65,13 +67,13 @@ document.querySelectorAll('input[data-utc]').forEach(function(input) {
     }
   }
 });
-// Convert datetime-local (user's local time) to UTC ISO before submit
+// Convert picker local time to UTC ISO for hidden inputs on submit
 document.querySelector('form').addEventListener('submit', function() {
-  ['start_date', 'expiry_date'].forEach(function(name) {
-    var input = document.getElementById(name);
-    if (input && input.value) {
-      var d = new Date(input.value);
-      if (!isNaN(d)) input.value = d.toISOString();
+  [['start_date_picker', 'start_date'], ['expiry_date_picker', 'expiry_date']].forEach(function(pair) {
+    var picker = document.getElementById(pair[0]);
+    var hidden = document.getElementById(pair[1]);
+    if (picker.value) {
+      hidden.value = new Date(picker.value).toISOString();
     }
   });
 });