Added a getDuration method to SG_iCal_VEvent

blocks/SG_iCal_VEvent.php

@@ -122,6 +122,14 @@ class SG_iCal_VEvent {
 		return $this->end;
 	}
 	
+	/**
+	 * Returns the duration of this event in seconds
+	 * @return int
+	 */
+	public function getDuration() {
+		return $this->end - $this->start;
+	}
+	
 	/**
 	 * Calculates the timestamp from a DT line.
 	 * @param $line SG_iCal_Line