borisyankov/DefinitelyTyped — pull request #2617 by DickvdBrink (2014-08-04 08:52:27+00:00)
Title: MomentJs: Fixed some return values and made parameters optional

You can find info about my changes in the i18n section.
The docs don't clearly state the return values (although you can find it in the examples)

docs: http://momentjs.com/docs/#/i18n/