diff --git a/includes/model/ShiftsFilter.php b/includes/model/ShiftsFilter.php
index 044b32dd..ff1f5d40 100644
--- a/includes/model/ShiftsFilter.php
+++ b/includes/model/ShiftsFilter.php
@@ -9,6 +9,12 @@ namespace Engelsystem;
  */
 class ShiftsFilter {
 
+  /**
+   * How long can the time interval be?
+   */
+  const MAX_DURATION = 86400;
+ // one day
+  
   /**
    * Shift is completely full.
    */
@@ -63,6 +69,9 @@ class ShiftsFilter {
   }
 
   public function setEndTime($endTime) {
+    if ($endTime - $this->startTime > ShiftsFilter::MAX_DURATION) {
+      $endTime = $this->startTime + ShiftsFilter::MAX_DURATION;
+    }
     $this->endTime = $endTime;
   }