Loading locales in NodeJS is super easy. If there is a locale file in moment/locale/ named after that key, import it first, then call moment.locale to load it.

var moment = require('moment');
// import moment from 'moment';

// import locale file(s)
import 'moment/locale/fr';

moment(1316116057189).fromNow(); // il y a 6 ans

To save the step of loading individual locales (i.e. just load them all), import the moment/min/moment-with-locales module instead.

import moment from 'moment/min/moment-with-locales';

moment(1316116057189).fromNow(); // vor 6 Jahren

If you want your locale supported, create a pull request to the develop branch with the required locale and unit test files.