By default, moment objects are created in the local time zone.
Local time zone - it's a time zone which is set in a browser or on your node.js server.

To change the default time zone, use with a valid time zone."America/New_York");

To reset the default time zone to local, use with no arguments.;

This is a global setting (shared by all modules).

Subsequent calls to will not affect existing moment objects or their clones.