diff --git a/ui/jquery.ui.datepicker.js b/ui/jquery.ui.datepicker.js
index ffc57266c..e4196bedd 100644
--- a/ui/jquery.ui.datepicker.js
+++ b/ui/jquery.ui.datepicker.js
@@ -1804,12 +1804,6 @@ function extendRemove(target, props) {
 	return target;
 };
 
-/* Determine whether an object is an array. */
-function isArray(a) {
-	return (a && (($.browser.safari && typeof a == 'object' && a.length) ||
-		(a.constructor && a.constructor.toString().match(/\Array\(\)/))));
-};
-
 /* Invoke the datepicker functionality.
    @param  options  string - a command, optionally followed by additional parameters or
 	                Object - settings for attaching new datepicker functionality