How to parse date time in UTC?

Question

I have a string like "10/14/2014 5:30:00 AM". I need to parse it as a UTC string. But when I execute moment.utc("10/14/2014 5:30:00 AM").format() I get "2014-10-13T22:30:00+00:00" while I expected to get "2014-10-14T12:30:00+00:00".

How can I make momentJS believe my string a UTC string and parse it without shifting time according to local timezone (+7 in my case)?

Answer 1

This is indeed a bug, and I filed it here. The problem occurs whenever you allow moment to fall back to the browser's parser. If you watch in your browser's debug console when you run this code, you'll see the following warning:

Deprecation warning: moment construction falls back to js Date. This is discouraged and will be removed in upcoming major release. Please refer to https://github.com/moment/moment/issues/1407 for more info.

The warning is normal, telling you not to use moment in a way that falls back to to the JavaScript Date object's parser. You can avoid this by providing a format string.

In general, passing values in m/d/y format without a format string is a bad idea, because not all users will have that format setting in their browser. A value like 1/4/2014 could be interpreted as January 4th, or as April 1st.

To explicitly tell moment to parse in a particular format, pass the format string like this:

moment.utc("10/14/2014 5:30:00 AM", "M/D/YYYY h:mm:ss a")

Answer 2

I find the exact same behavior which seems like a bug to me since utc() shouldn't infer a timezone when one isn't present.

The solution is to re-format your date before calling utc(). I find that the array syntax and ISO 8601 format work fine:

// Array format - Works
moment.utc([2014, 10, 14, 10, 05]).format()

// Nope
moment.utc("10/14/2014 5:30:00 AM").format();

// ISO 8601 - Works
moment.utc("2014-10-14 05:30:00").format();

JSFiddle: http://jsfiddle.net/0qw54nrb/