Moment.js gives Invalid date in Firefox

It's recommended to avoid using moment parsing with custom format. As the documentation states:

Warning: Browser support for parsing strings is inconsistent. Because there is no specification on which formats should be supported, what works in some browsers will not work in other browsers.

For consistent results parsing anything other than ISO 8601 strings, you should use String + Format.

In your case, the code for consistent parsing will be:

moment('2016-Jan-02 02:00 AM', 'YYYY-MMM-DD HH:mm A')

You're not specifying a format for parsing the string 2016-Jan-02. So moment falls back to the native Date object, which is inconsistent across the different browsers. To parse the date consistently, include a format string along with it.

e.g.

moment("2016-Jan-02", "DD-MMM-YYYY")

Then if you want to format the moment object as a string, you can do what you were doing before:

moment("2016-Jan-02", "DD-MMM-YYYY").format("DD-MM-YYYY")

which returns the string 02-01-2016 in both browsers.