How can I get the current date based on UTC Offset? For example, the UTC Offset for Australia is UTC +10:00 where it is already May 24th.

I can get UTC date and hour but can't find any Date methods that factor in UTC Offset.

How can I get the current date based on UTC Offset? For example, the UTC Offset for Australia is UTC +10:00 where it is already May 24th.

I can get UTC date and hour but can't find any Date methods that factor in UTC Offset.

• javascript
• date

• 1 The easier way would probably be to use moment.js: momentjs./timezone – Frax Commented May 23, 2016 at 19:25
• Australia and its territories have several time zones, ranging from +05:00 to +11:00. – RobG Commented May 24, 2016 at 4:47

3 Answers 3

Once you have the offset (in this case 10 hours) use this function:

function getDateWithUTCOffset(inputTzOffset){
    var now = new Date(); // get the current time

    var currentTzOffset = -now.getTimezoneOffset() / 60 // in hours, i.e. -4 in NY
    var deltaTzOffset = inputTzOffset - currentTzOffset; // timezone diff

    var nowTimestamp = now.getTime(); // get the number of milliseconds since unix epoch 
    var deltaTzOffsetMilli = deltaTzOffset * 1000 * 60 * 60; // convert hours to milliseconds (tzOffsetMilli*1000*60*60)
    var outputDate = new Date(nowTimestamp + deltaTzOffsetMilli) // your new Date object with the timezone offset applied.

    return outputDate;
}

In your case you would use:

var timeInAustralia = getDateWithUTCOffset(10);

This will return a Date object. You still need to format the date to your liking.

I agree with @Frax, Moment is a great library if you don't mind adding additional dependencies to your project.

Good luck

Using Moment.js and Moment Timezone it's very easy:

moment().tz("Australia/Sydney").format()

Date objects have UTC methods, so if you have an offset like +10:00 you can simply apply it to the UTC time and then read the resulting UTC values. The offset can be applied as hours and minutes, or converted to a single value and applied, e.g.

/*  Return a date in yyyy-mm-dd format for the provided offset
**  @param {string} offset - offset from GMT in format +/-hh:mm
**                         - default sign is +, default offset is 00:00
**  @returns {string} date at pffset in format yyyy-mm-dd
*/
function dateAtOffset(offset){
  function z(n){return (n<10?'0':'') + n}
  var d = new Date();
  var sign = /^\-/.test(offset)? -1 : +1;
  offset = offset.match(/\d\d/g) || [0,0];
  d.setUTCMinutes(d.getUTCMinutes() + sign*(offset[0]*60 + offset[1]*1))
  return d.getUTCFullYear() + '-' + z(d.getUTCMonth() + 1) + '-' + z(d.getUTCDate());
}

var offset = '+10:00';
document.write('The date at GMT' + offset + ' is: ' + dateAtOffset(offset));

You can also adjust a date for the offset and read "local" values:

function timeAtOffset(offset) {
  var d = new Date();
  var sign = /^\-/.test(offset)? -1 : 1;
  offset = offset.match(/\d\d/g) || [0,0];
  d.setMinutes(d.getMinutes() + d.getTimezoneOffset() + sign*(offset[0]*60 + offset[1]*1));
  return d;
}

var offset = '-04:00';
document.write('Time at GMT' + offset + ' is: ' + timeAtOffset(offset))

Note however that the default toString will report the local time zone offset, not the one to which it has been adjusted, so be careful when using such an object.