diff --git a/src/openseadragon.js b/src/openseadragon.js
index 22ca56e9..dad43393 100644
--- a/src/openseadragon.js
+++ b/src/openseadragon.js
@@ -952,6 +952,20 @@ window.OpenSeadragon = window.OpenSeadragon || function( options ){
         },
 
 
+        /**
+         * Returns the current milliseconds, using Date.now() if available
+         * @name $.now
+         * @function
+         */
+        now: function( ) {
+          if (Date.now) {
+            $.now = Date.now;
+          } else {
+            $.now = function() { return new Date().getTime(); };
+          }
+        },
+
+
         /**
          * Ensures an image is loaded correctly to support alpha transparency.
          * Generally only IE has issues doing this correctly for formats like