Node.js - How to format a date string in UTC

If you're using Node.js, you're sure to have EcmaScript 5, and so Date has a toISOString method. You're asking for a slight modification of ISO8601:

new Date().toISOString()
> '2012-11-04T14:51:06.157Z'

So just cut a few things out, and you're set:

new Date().toISOString().
  replace(/T/, ' ').      // replace T with a space
  replace(/\..+/, '')     // delete the dot and everything after
> '2012-11-04 14:55:45'

Or, in one line: new Date().toISOString().replace(/T/, ' ').replace(/\..+/, '')

ISO8601 is necessarily UTC (also indicated by the trailing Z on the first result), so you get UTC by default (always a good thing).

OK, since no one has actually provided an actual answer, here is mine.

A library is certainly the best bet for handling dates and times in a standard way. There are lots of edge cases in date/time calculations so it is useful to be able to hand-off the development to a library.

Here is a list of the main Node compatible time formatting libraries:

• Moment.js [thanks to Mustafa] "A lightweight (4.3k) javascript date library for parsing, manipulating, and formatting dates" - Includes internationalization, calculations and relative date formats
• strftime - Just what it says, nice and simple
• dateutil - This is the one I've typically used though I think I may switch to Moment
• node-formatdate
• TimeTraveller - "Time Traveller provides a set of utility methods to deal with dates. From adding and substracting, to formatting. Time Traveller only extends date objects that it creates, without polluting the global namespace."
• Tempus [thanks to Dan D] - UPDATE: this can also be used with Node and deployed with npm, see the docs

There are also non-Node libraries:

• Datejs [thanks to Peter Olson] - not packaged in npm or GitHub so not quite so easy to use with Node

I have nothing against libraries in general. In this case a general purpose library seems overkill, unless other parts of the application process dates heavily.

Writing small utility functions such as this is also a useful exercise for both beginning and accomplished programmers alike and can be a learning experience for the novices amongst us.

function dateFormat (date, fstr, utc) {
  utc = utc ? 'getUTC' : 'get';
  return fstr.replace (/%[YmdHMS]/g, function (m) {
    switch (m) {
    case '%Y': return date[utc + 'FullYear'] (); // no leading zeros required
    case '%m': m = 1 + date[utc + 'Month'] (); break;
    case '%d': m = date[utc + 'Date'] (); break;
    case '%H': m = date[utc + 'Hours'] (); break;
    case '%M': m = date[utc + 'Minutes'] (); break;
    case '%S': m = date[utc + 'Seconds'] (); break;
    default: return m.slice (1); // unknown code, remove %
    }
    // add leading zero if required
    return ('0' + m).slice (-2);
  });
}

/* dateFormat (new Date (), "%Y-%m-%d %H:%M:%S", true) returns 
   "2012-05-18 05:37:21"  */

There's a library for conversion ...

npm install dateformat

Than write your requirement :

var dateFormat = require('dateformat');

Than bind the value :

var day=dateFormat(result.request_date, "yyyy-mm-dd h:MM:ss");

You can use one of the many module available for formatting dates. @Julian-Knight gave a pretty good list in his answer.

Also, another great way to achieve what you are looking for is to use the method provided in the Date object as followed:

var ts_hms = new Date(UTC);

console.log(
    ts_hms.getFullYear() + '-' + 
    ("0" + (ts_hms.getMonth() + 1)).slice(-2) + '-' + 
    ("0" + (ts_hms.getDate() + 1)).slice(-2) + ' ' +
    ("0" + ts_hms.getHours()).slice(-2) + ':' +
    ("0" + ts_hms.getMinutes()).slice(-2) + ':' +
    ("0" + ts_hms.getSeconds()).slice(-2));

It looks really dirty, but it should be working fine with JavaScript core methods :)

The javascript library sugar.js (http://sugarjs.com/) has functions to format dates

Example:

Date.create().format('{dd}/{MM}/{yyyy} {hh}:{mm}:{ss}.{fff}')

I needed a simple formatting library without the bells and whistles of locale and language support. So I modified

http://www.mattkruse.com/javascript/date/date.js

and used it. See https://github.com/adgang/atom-time/blob/master/lib/dateformat.js

The documentation is pretty clear.

The best option is to use the dateformat library:

• npm install dateformat
• var dateFormat = require('dateformat');
• var day=dateFormat(result.request_date, "yyyy-mm-dd h:MM:ss");