Moment.js Convert Local time to UTC time does work

Question

I would like to use Moment.js to convert a local time to UTC equivalent. I believe that I have the correct method in place, but it does not alter the time.

I'm in Sydney Australian +11 and expect the UTC time to be 11 hours earlier.

Internally on the moment object the isUTC flag changes from false to true, but the time does NOT shift, am I meant to use a different technique for this.

How do I actually get the current UTC date out of this object

Before Conversion

var val = '18/03/2015';
var selectedDate = moment(val, 'DD/MM/YYYY');

After Conversion

var a = selectedDate.utc()

Ambassador

Does this answer your question? How to convert from GMT/UTC to local time and back using momentjs? – Vandalism

Answer 1

I just tried this code and it seems like I get the correct UTC time. I guess I just want to confirm that what I am doing is correct way to access the UTC time from moment.js

a.format("YYYY-MM-DD HH:mm:ssZ")

I found that my usage pattern of in my application was incorrect

selectedDate.utc().format(fullFormat)

It should have been

moment.utc(selectedDate).format(fullFormat)

Ambassador

That last code snippet is correct. Take a look at momentjs.com/docs/#/parsing/utc . In order to get into utc mode, you should create a new moment. Though in my own testing, I seem to be able to call .utc() on an existing moment successfully, so who knows. – Kinney

not moment().utc(..., but moment.utc(..., I guess :) – Bigoted

@Bigoted is right, you should use moment.utc(datetime).format(MOMENT_UTC_DATE_TIME_FORMAT) – Killigrew

if selectedDate be a timestamp in milisecond, it dos not work. why? – Flange

Answer 2

This works

moment(date_to_convert).utc().format("YYYY-MM-DD HH:mm:ss");

Torch

Answer 3

The question is old, but I also faced it. It may be useful to someone:

Using the method of utcOffset() to calculate the UTC time:

selectedDate = (moment(selectedDate).add(-(moment().utcOffset()), 'm'));

And explicitly specify UTC:

selectedDate = moment.parseZone(selectedDate).utc().format();

Iscariot

I think I had the reverse problem... dates, in JSON, were utc but interpreted as local, so I had to add the utc offset. One thing though, I think you really want to use the selectedDate to determine the offset as it will change... this was my code: const correctedDateTime = m.add((moment(utcDate).utcOffset()), 'm'); – Sihonn

Answer 4

This is how you do it using moment-timezone

moment.tz(localDate, localTimeZone).utc()

Invalidate

Answer 5

This worked for me !!

selectedDate = moment(selectedDate).add(moment(selectedDate).utcOffset(), 'm').utc().format()

Skewback

This does not work if the offset needs to be subtracted. – Killick

It does work for the subtraction cases as the utcOffset returns a negative value for such cases – Quartic

Answer 6

Create a local moment object from you local time and convert it to UTC then format it, then create a new UTC moment from that formatted UTC string

var localDateString = '24/04/2019';
var localDateStringFormat = 'DD/MM/YYYY';

var utcMoment = moment.utc(moment(localDateString, localDateStringFormat ).utc().format('YYYY-MM-DD HH:mm:ssZ'))

console.log(utcMoment);

<script src="https://momentjs.com/downloads/moment.js"></script>

Commendatory

Answer 7

After few frustrating hours, I found what was the problem

Short Answer: To convert time to utc, we need to use format()

Long Answer: Take the example

moment.utc(1559586600000).format('LLL')

.utc sets the isUTC flag to true.

When logging the date, the d key always shows the time in local timezone. (Which makes us believe its not working properly - as shown in your screenshot)

But we need to use .format to get the date/time in UTC format.

The above code returns June 3, 2019 6:30 PM which is the correct UTC time.

Lowercase

Answer 8

const moment = require('moment-timezone');
const dateTime='2020-12-21'
const timezone='America/Anchorage'
const dateTimeInUtc = moment(dateTime).tz(timezone).utc().format();
console.log('dateTimeInUtc',dateTimeInUtc);

Pothole

Answer 9

After few frustrating hours, I found what was the problem

Short Answer: To convert time to utc, we need to use format()

Long Answer: Take the example

moment.utc(1559586600000).format('LLL')

.utc sets the isUTC flag to true.

When logging the date, the d key always shows the time in local timezone. (Which makes us believe its not working properly - as shown in your screenshot)

But we need to use .format to get the date/time in UTC format.

The above code returns June 3, 2019 6:30 PM which is the correct UTC time.

Scagliola

Answer 10

const moment = require('moment-timezone');
const dateTime='2020-12-21'
const timezone='America/Anchorage'
const dateTimeInUtc = moment(dateTime).tz(timezone).utc().format();
console.log('dateTimeInUtc',dateTimeInUtc);

Scagliola

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You should probably merge this with your earlier answer, or otherwise explain how the two different answers relate to each other. – Causation