diff --git a/includes/classes/Event.php b/includes/classes/Event.php
index 994ed8140..e24ebe64d 100644
--- a/includes/classes/Event.php
+++ b/includes/classes/Event.php
@@ -202,7 +202,7 @@ function __construct ( $name, $description, $date, $time, $id, $extForID,
     $this->_calType = $calType;
     $this->_location = $location;
     $this->_url = $url;
-    $this->_dueDate  = $dueDate;
+    $this->_dueDate  = empty($dueDate) ? '' : $dueDate;
     $this->_dueTime  = sprintf ( "%06d", $dueTime );
     $this->_due = $dueDate . sprintf ( "%06d", $dueTime );
     $this->_percent = $percent;
diff --git a/includes/functions.php b/includes/functions.php
index 4141d9631..8dd9c6000 100644
--- a/includes/functions.php
+++ b/includes/functions.php
@@ -821,14 +821,14 @@ function date_to_epoch( $d, $gmt = true ) {
 
   if ( $gmt )
     return gmmktime ( $dH, $di, $ds,
-      substr ( $d, 4, 2 ),
-      substr ( $d, 6, 2 ),
-      substr ( $d, 0, 4 ) );
+      (int)substr ( $d, 4, 2 ),
+      (int)substr ( $d, 6, 2 ),
+      (int)substr ( $d, 0, 4 ) );
   else
     return mktime ( $dH, $di, $ds,
-      substr ( $d, 4, 2 ),
-      substr ( $d, 6, 2 ),
-      substr ( $d, 0, 4 ) );
+      (int)substr ( $d, 4, 2 ),
+      (int)substr ( $d, 6, 2 ),
+      (int)substr ( $d, 0, 4 ) );
 }