Edit

Editing: cy.js

//! moment.js locale configuration

;(function (global, factory) {
   typeof exports === 'object' && typeof module !== 'undefined'
       && typeof require === 'function' ? factory(require('../moment')) :
   typeof define === 'function' && define.amd ? define(['../moment'], factory) :
   factory(global.moment)
}(this, (function (moment) { 'use strict';

var cy = moment.defineLocale('cy', {
        months: 'Ionawr_Chwefror_Mawrth_Ebrill_Mai_Mehefin_Gorffennaf_Awst_Medi_Hydref_Tachwedd_Rhagfyr'.split('_'),
        monthsShort: 'Ion_Chwe_Maw_Ebr_Mai_Meh_Gor_Aws_Med_Hyd_Tach_Rhag'.split('_'),
        weekdays: 'Dydd Sul_Dydd Llun_Dydd Mawrth_Dydd Mercher_Dydd Iau_Dydd Gwener_Dydd Sadwrn'.split('_'),
        weekdaysShort: 'Sul_Llun_Maw_Mer_Iau_Gwe_Sad'.split('_'),
        weekdaysMin: 'Su_Ll_Ma_Me_Ia_Gw_Sa'.split('_'),
        weekdaysParseExact : true,
        // time formats are the same as en-gb
        longDateFormat: {
            LT: 'HH:mm',
            LTS : 'HH:mm:ss',
            L: 'DD/MM/YYYY',
            LL: 'D MMMM YYYY',
            LLL: 'D MMMM YYYY HH:mm',
            LLLL: 'dddd, D MMMM YYYY HH:mm'
        },
        calendar: {
            sameDay: '[Heddiw am] LT',
            nextDay: '[Yfory am] LT',
            nextWeek: 'dddd [am] LT',
            lastDay: '[Ddoe am] LT',
            lastWeek: 'dddd [diwethaf am] LT',
            sameElse: 'L'
        },
        relativeTime: {
            future: 'mewn %s',
            past: '%s yn ôl',
            s: 'ychydig eiliadau',
            ss: '%d eiliad',
            m: 'munud',
            mm: '%d munud',
            h: 'awr',
            hh: '%d awr',
            d: 'diwrnod',
            dd: '%d diwrnod',
            M: 'mis',
            MM: '%d mis',
            y: 'blwyddyn',
            yy: '%d flynedd'
        },
        dayOfMonthOrdinalParse: /\d{1,2}(fed|ain|af|il|ydd|ed|eg)/,
        // traditional ordinal numbers above 31 are not commonly used in colloquial Welsh
        ordinal: function (number) {
            var b = number,
                output = '',
                lookup = [
                    '', 'af', 'il', 'ydd', 'ydd', 'ed', 'ed', 'ed', 'fed', 'fed', 'fed', // 1af to 10fed
                    'eg', 'fed', 'eg', 'eg', 'fed', 'eg', 'eg', 'fed', 'eg', 'fed' // 11eg to 20fed
                ];
            if (b > 20) {
                if (b === 40 || b === 50 || b === 60 || b === 80 || b === 100) {
                    output = 'fed'; // not 30ain, 70ain or 90ain
                } else {
                    output = 'ain';
                }
            } else if (b > 0) {
                output = lookup[b];
            }
            return number + output;
        },
        week : {
            dow : 1, // Monday is the first day of the week.
            doy : 4  // The week that contains Jan 4th is the first week of the year.
        }
    });

return cy;

})));