Index: globals.php
===================================================================
--- globals.php	(revision 15512)
+++ globals.php	(working copy)
@@ -680,6 +680,7 @@
 	 * @static
 	 * @param int $timestamp
 	 * @return DateTime
+	 * @access public
 	 */
 	public static function dateFromTimestamp($timestamp)
 	{
@@ -694,6 +695,23 @@
 
 		return $date;
 	}
+
+	/**
+	 * Returns timestamp from given DateTime class instance
+	 *
+	 * @static
+	 * @param DateTime $date_time
+	 * @return int|string
+	 * @access public
+	 */
+	public static function timestampFromDate(DateTime $date_time)
+	{
+		if ( version_compare(PHP_VERSION, '5.3.0', '<') ) {
+			return $date_time->format('U');
+		}
+
+		return $date_time->getTimestamp();
+	}
 }
 
 /**