change date format in shift table

fixes #202

includes/pages/user_shifts.php

@@ -210,7 +210,7 @@ function user_shifts() {
       if ($result === false)
         engelsystem_error('Unable to delete shift.');
 
-      engelsystem_log("Deleted shift " . $shift['name'] . " from " . date("y-m-d H:i", $shift['start']) . " to " . date("y-m-d H:i", $shift['end']));
+      engelsystem_log("Deleted shift " . $shift['name'] . " from " . date("Y-m-d H:i", $shift['start']) . " to " . date("Y-m-d H:i", $shift['end']));
       success(_("Shift deleted."));
       redirect(page_link_to('user_shifts'));
     }
@@ -568,7 +568,7 @@ function view_user_shifts() {
                   'RID' => $room['id'],
                   'Name' => $room['name']
               ]) . '<br />';
-              $shifts_row .= '<a href="' . shift_link($shift) . '">' . date('d.m. H:i', $shift['start']);
+              $shifts_row .= '<a href="' . shift_link($shift) . '">' . date('Y-m-d H:i', $shift['start']);
               $shifts_row .= " &ndash; ";
               $shifts_row .= date('H:i', $shift['end']);
               $shifts_row .= "<br /><b>";