Moment Clone1.2.0+

moment(Moment);

All moments are mutable. If you want a clone of a moment, you can do so implicitly or explicitly.

Calling moment() on a moment will clone it.

var a = moment([2012]);
var b = moment(a);
a.year(2000);
b.year(); // 2012

Additionally, you can call moment#clone to clone a moment.

var a = moment([2012]);
var b = a.clone();
a.year(2000);
b.year(); // 2012