diff --git a/django/contrib/admin/static/admin/js/core.js b/django/contrib/admin/static/admin/js/core.js
index 3ca8ad0f9a0..ab776509ba7 100644
--- a/django/contrib/admin/static/admin/js/core.js
+++ b/django/contrib/admin/static/admin/js/core.js
@@ -108,12 +108,6 @@ function findPosY(obj) {
 //-----------------------------------------------------------------------------
 // Date object extensions
 // ----------------------------------------------------------------------------
-Date.prototype.getCorrectYear = function() {
-    // Date.getYear() is unreliable --
-    // see http://www.quirksmode.org/js/introdate.html#year
-    var y = this.getYear() % 100;
-    return (y < 38) ? y + 2000 : y + 1900;
-}
 
 Date.prototype.getTwelveHours = function() {
     hours = this.getHours();
@@ -149,10 +143,6 @@ Date.prototype.getTwoDigitSecond = function() {
     return (this.getSeconds() < 10) ? '0' + this.getSeconds() : this.getSeconds();
 }
 
-Date.prototype.getISODate = function() {
-    return this.getCorrectYear() + '-' + this.getTwoDigitMonth() + '-' + this.getTwoDigitDate();
-}
-
 Date.prototype.getHourMinute = function() {
     return this.getTwoDigitHour() + ':' + this.getTwoDigitMinute();
 }