Date formatter for javascript

Question

I just coded this formatter to format timestamps in javascript (I tied it to underscore for convenience), any remark?

_.toDate = function(epoch, format, locale) {    
    var date = new Date(epoch),
        format = format || 'dd/mm/YY',
        locale = locale || 'en'
        dow = {};

    dow.en = [
        'Sunday',
        'Monday',
        'Tuesday',
        'Wednesday',
        'Thursday',
        'Friday',
        'Saturday'
    ];

    var formatted = format
        .replace('D', dow[locale][date.getDay()])
        .replace('dd', ("0" + date.getDate()).slice(-2))
        .replace('mm', ("0" + (date.getMonth() + 1)).slice(-2))
        .replace('yyyy', date.getFullYear())
        .replace('yy', (''+date.getFullYear()).slice(-2))
        .replace('hh', date.getHours())
        .replace('mn', date.getMinutes());

    return formatted;
}

usage

_.toDate($.now(), "dd-mm-yy at hh:mn");
// Will output:
"27-03-13 at 17:20"

Answer 1

I would use a library that is designed for this, such as Moment.js. It is a lot more flexible, and has internationalization support also.

Answer 2

What happens when you add the Hungarian locale

dow.hu = [
    'vasárnap',
    'hétfő',
    'kedd',
    'szerda',
    'csütörtök',
    'péntek',
    'szombat'
]

and try to format

_.toDate(new Date(2013, 07, 30, 12, 0, 0, 0), 'D dd mm, yy', 'hu');

?