diff --git a/include/entwicklungsteam.class.php b/include/entwicklungsteam.class.php
index fd3dd782f..a91ff10be 100644
--- a/include/entwicklungsteam.class.php
+++ b/include/entwicklungsteam.class.php
@@ -169,18 +169,23 @@ class entwicklungsteam extends basis_db
 			return false;
 		}
 
-		$beginnParts = explode('-', $this->beginn);
-		if (!checkdate((int)$beginnParts[1], (int)$beginnParts[2], (int)$beginnParts[0]))
+		if($this->beginn != '')
 		{
-			$this->errormsg = 'Anfangsdatum ist ungültig';
-			return false;
+			$beginnParts = explode('-', $this->beginn);
+			if (!checkdate((int)$beginnParts[1], (int)$beginnParts[2], (int)$beginnParts[0])) {
+				$this->errormsg = 'Anfangsdatum ist ungültig';
+				return false;
+			}
 		}
 
-		$endeParts = explode('-', $this->ende);
-		if (!checkdate((int)$endeParts[1], (int)$endeParts[2], (int)$endeParts[0]))
+		if($this->ende != '')
 		{
-			$this->errormsg = 'Endedatum ist ungültig';
-			return false;
+			$endeParts = explode('-', $this->ende);
+			if (!checkdate((int)$endeParts[1], (int)$endeParts[2], (int)$endeParts[0]))
+			{
+				$this->errormsg = 'Endedatum ist ungültig';
+				return false;
+			}
 		}
 
 		return true;