Fix #3908: DateHelper::parseDateTime() returns invalid date if given value is not parsable

protected/humhub/docs/CHANGELOG.md

@@ -1,6 +1,10 @@
 HumHub Change Log
 =================
 
+1.4.4 (Unreleased)
+---------------------
+- Fix #3908: `DateHelper::parseDateTime()` returns invalid date if given value is not parsable
+
 1.4.3 (March 4, 2020)
 ---------------------
 - Fix #3887: CSS presentation issue for tables wider than the container and videos missing borders (areasas)

protected/humhub/libs/DateHelper.php

@@ -89,12 +89,17 @@ class DateHelper
      * @param string $value date value
      * @param string $pattern pattern
      * @param string $timeValue optional time value
-     * @return int timestamp in utc
+     * @return int|false timestamp in utc or false in case value was could not be parsed
      * @throws \Exception
      */
     public static function parseDateTime($value, $pattern = 'Y-m-d', $timeValue = null)
     {
         $ts = self::parseDateTimeToTimestamp($value, $timeValue);
+
+        if($ts === false) {
+            return false;
+        }
+
         $dt = new \DateTime();
         $dt->setTimestamp($ts);