http://coffeescriptcookbook.com/chapters/classes_and_objects/cloning v1 = new Date('1982-2-2') v2 = clone v1 console.dir v1 + ' ' + v2 Output: 'Tue Feb 02 1982 00:00:00 GMT+0800 (CST) Wed Apr 11 2012 17:56:14 GMT+0800 (CST)'