How do you convert a JavaScript date to UTC?

Question

Suppose a user of your website enters a date range.

2009-1-1 to 2009-1-3

You need to send this date to a server for some processing, but th

Answer 1

Convert to ISO without changing date/time

var now = new Date(); // Fri Feb 20 2015 19:29:31 GMT+0530 (India Standard Time) 
var isoDate = new Date(now.getTime() - now.getTimezoneOffset() * 60000).toISOString();
//OUTPUT : 2015-02-20T19:29:31.238Z

Convert to ISO with change in date/time(date/time will be changed)

isoDate = new Date(now).toISOString();
//OUTPUT : 2015-02-20T13:59:31.238Z 

Fiddle link