diff --git a/includes/pages/admin_shifts.php b/includes/pages/admin_shifts.php
index d697a496..817e9b9a 100644
--- a/includes/pages/admin_shifts.php
+++ b/includes/pages/admin_shifts.php
@@ -114,7 +114,7 @@ function admin_shifts()
                 if (
                     $request->has('change_hours')
                     && preg_match(
-                        '/^(\d{2}(,|$))/',
+                        '/^((\d{2}(:\d{2})?(,|$))*)/',
                         trim(str_replace(' ', '', $request->input('change_hours')))
                     )
                 ) {
@@ -216,10 +216,18 @@ function admin_shifts()
                 $day = parse_date('Y-m-d H:i', date('Y-m-d', $start) . ' 00:00');
                 $change_index = 0;
                 // Ersten/nächsten passenden Schichtwechsel suchen
-                foreach ($change_hours as $i => $change_hour) {
-                    if ($start < $day + $change_hour * 60 * 60) {
+                foreach ($change_hours as $i => $change_time) {
+                    if(!preg_match('/\d{2}:\d{2}/',$change_time)) {
+                        $change_time = $change_time.":00";
+                    }
+
+                    $change_time = explode(':',$change_time);
+                    $change_hour = $change_time[0];
+                    $change_minute = $change_time[1];
+
+                       if ($start < $day + $change_hour * 60 * 60 + $change_minute * 60) {
                         $change_index = $i;
-                    } elseif ($start == $day + $change_hour * 60 * 60) {
+                    } elseif ($start == $day + $change_hour * 60 * 60  + $change_minute * 60) {
                         // Start trifft Schichtwechsel
                         $change_index = ($i + count($change_hours) - 1) % count($change_hours);
                         break;
@@ -231,7 +239,19 @@ function admin_shifts()
                 $shift_start = $start;
                 do {
                     $day = parse_date('Y-m-d H:i', date('Y-m-d', $shift_start) . ' 00:00');
-                    $shift_end = $day + $change_hours[$change_index] * 60 * 60;
+
+                    $change_time=$change_hours[$change_index];
+                    if(!preg_match('/\d{2}:\d{2}/',$change_time)) {
+                        $change_time = $change_time.":00";
+                    }
+
+                    $change_time = explode(':',$change_time);
+                    $change_hour = $change_time[0];
+                    $change_minute = $change_time[1];
+
+
+                    $shift_end = $day + $change_hour * 60 * 60 + $change_minute * 60;
+
 
                     if ($shift_end > $end) {
                         $shift_end = $end;