diff --git a/gestion/lib/Helpers/VCalendarHelpers.php b/gestion/lib/Helpers/VCalendarHelpers.php
index 2d977e7..cc09064 100644
--- a/gestion/lib/Helpers/VCalendarHelpers.php
+++ b/gestion/lib/Helpers/VCalendarHelpers.php
@@ -40,6 +40,8 @@ class VCalendarHelpers
         $endTimeValue = "";
         $totalHours = 0;
         $totalWorkedHours = 0;
+        $dateStart = null;
+        $dateEnd = null;
         if($vCalendarString != ""){
             $dateStart = self::GetDateStartOrDateEndFromVCalendarString("DTSTART", $vCalendarString);
             if($dateStart != null){