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Moment unable to convert in different timezone

My server is returning me dates in UTC and I want to convert them to the timezone of the server (even if the customer browser is in a different timezone !)
Here is one example, my server is in Europe/Berlin.
var dateAsString = '2022-04-11T22:00:00.000Z'; // 2022-04-12 00:00:00 in Europe/Berlin
var utcDate = moment.utc(dateAsString);
console.log(utcDate.format());
var serverTzDate = utcDate.clone().tz('Europe/Berlin');
console.log(serverTzDate.format());
console.log(serverTzDate.format());
var test = moment.utc('2022-04-11T22:00:00.000Z').tz('Europe/Berlin').format();
console.log(test);
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.2/moment.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.34/moment-timezone-with-data-10-year-range.js"></script>
If my browser is in the Europe/Berlin timezone the output is correct:
2022-04-11T22:00:00Z
2022-04-12T00:00:00+02:00
2022-04-12T00:00:00+02:00
But if I change my timezone (for my example I took Pacific/Niue), then the result is totally wrong, I suppose moment is doing something with the timezone of the browser but how to avoid this ? Here is the output:
2022-04-11T09:00:00Z
2022-04-11T11:00:00+02:00
2022-04-11T11:00:00+02:00
I need to have the date in the timezone of the server and not in the timezone of the browser
With another timezone: Pacific/Kiritimati (-840)
2022-04-12T10:00:00Z // Wanted 2022-04-11T22:00:00Z (UTC Date as entered)
2022-04-12T12:00:00+02:00 // Wanted 2022-04-12T00:00:00Z (Converted in Europe/Berlin)
2022-04-12T12:00:00+02:00 // Wanted 2022-04-12T00:00:00Z (Converted in Europe/Berlin)
2022-04-12T12:00:00+02:00 // Wanted 2022-04-12T00:00:00Z (Converted in Europe/Berlin)
Again all the dates are wrong, moment seems not able to parse my date as an UTC date ? It apply the timezone offset of the browser even if I'm using the utc method

moment.utc('2022-04-11T22:00:00.000Z').tz('Europe/Berlin').format()
please check this document. https://momentjs.com/timezone/docs/#/using-timezones/
below is my code result, whatever timezone you changed, the result is '2022-04-12T00:00:00+02:00'

Local time zone not displayed while formatting OffsetDataTime using moment js [duplicate]

What is the best way to get client's timezone and convert it to some other timezone when using moment.js and moment-timezone.js
I want to find out what is clients timezone and later convert his date and time into some other timezone.
Does anybody has experience with this?

When using moment.js, use:
var tz = moment.tz.guess();
It will return an IANA time zone identifier, such as America/Los_Angeles for the US Pacific time zone.
It is documented here.
Internally, it first tries to get the time zone from the browser using the following call:
Intl.DateTimeFormat().resolvedOptions().timeZone
If you are targeting only modern browsers that support this function, and you don't need Moment-Timezone for anything else, then you can just call that directly.
If Moment-Timezone doesn't get a valid result from that function, or if that function doesn't exist, then it will "guess" the time zone by testing several different dates and times against the Date object to see how it behaves. The guess is usually a good enough approximation, but not guaranteed to exactly match the time zone setting of the computer.

var timedifference = new Date().getTimezoneOffset();
This returns the difference from the clients timezone from UTC time.
You can then play around with it as you like.

All current answers provide the offset differece at current time, not at a given date.
moment(date).utcOffset() returns the time difference in minutes between browser time and UTC at the date passed as argument (or today, if no date passed).
Here's a function to parse correct offset at the picked date:
function getUtcOffset(date) {
return moment(date)
.subtract(
moment(date).utcOffset(),
'minutes')
.utc()
}

Using Moment library, see their website -> https://momentjs.com/timezone/docs/#/using-timezones/converting-to-zone/
i notice they also user their own library in their website, so you can have a try using the browser console before installing it
moment().tz(String);
The moment#tz mutator will change the time zone and update the offset.
moment("2013-11-18").tz("America/Toronto").format('Z'); // -05:00
moment("2013-11-18").tz("Europe/Berlin").format('Z'); // +01:00
This information is used consistently in other operations, like calculating the start of the day.
var m = moment.tz("2013-11-18 11:55", "America/Toronto");
m.format(); // 2013-11-18T11:55:00-05:00
m.startOf("day").format(); // 2013-11-18T00:00:00-05:00
m.tz("Europe/Berlin").format(); // 2013-11-18T06:00:00+01:00
m.startOf("day").format(); // 2013-11-18T00:00:00+01:00
Without an argument, moment#tz returns:
the time zone name assigned to the moment instance or
undefined if a time zone has not been set.
var m = moment.tz("2013-11-18 11:55", "America/Toronto");
m.tz(); // America/Toronto
var m = moment.tz("2013-11-18 11:55");
m.tz() === undefined; // true

You can also get your wanted time using the following JS code:
new Date(`${post.data.created_at} GMT+0200`)
In this example, my received dates were in GMT+0200 timezone. Instead of it can be every single timezone. And the returned data will be the date in your timezone. Hope this will help anyone to save time

if the user's timezone is all you wanted then
const localtz = moment.tz.guess() // returns user's timezone
Additionally if you wanted to use it then the best way to convert a timestamp to user's timezone is
const time = moment.tz(response.timestamp)
const localtz = moment.tz.guess() // user's timezone
const date = time.clone().tz(localtz) // convert time to user's timezone
here localtz is the user's timezone and using it we can convert the timestamp to user's local time

First, you can find out the clients time zone using the following
let zoneVal = moment().tz(Intl.DateTimeFormat().resolvedOptions().timeZone).format('Z')
it will return you the GMT zone format for example +5:30 (colombo/srilanka & Delhi/India) or +6:00(Dhaka Bangladesh) depending on the region you are in.
secondly,
if you want to find out the time of a particular time zone , then do the following
moment.tz("Asia/Dhaka").format()
which will return you the time zone value in ISO format of Dhaka.

Using moment timezone you can get easily your local date-time
moment().utcOffset(0, true).format()

Converting a date, time and offset into an ISO8601 DateTime using moment.js and moment timezone

I am processing some itinerary data where the times and dates are all provided in the local timezone. I am adding this data to a database where I'd like to store all of the dates in UTC, with the proper timezone offset. I'm trying to process these dates with moment.js.
The input string for date/time is formatted like this 2020-07-12 13:00 and the timezone is in this format Europe/Amsterdam.
I want to end up with a string like:
2020-07-12T11:00:00+02:00
The trouble I'm having, is that moment converts my input time to either local time or utc if I use the .utc() method.
This code is getting me the correct result, but I don't understand why and I'm not sure if I can rely on its accuracy:
var offset = moment.tz(`Europe/Amsterdam`).utcOffset();
var m = moment(`2020-07-12 13:00`, 'YYYY-MM-DD HH:mm').utc().subtract(240 + offset + offset, 'minutes').utcOffset(offset); // (240 is my own UTC offset)
How can I simply input a date, time and timezone and end up with a correct ISO8601 DateTime?

If you are already using Moment and Moment-TimeZone in your app, then you can simply do the following:
const m = moment.tz('2020-07-12 13:00', 'YYYY-MM-DD HH:mm', 'Europe/Amsterdam');
m.format() //=> "2020-07-12T13:00:00+02:00"
However, the Moment team recommends using Luxon for new development. The equivalent is:
const dt = luxon.DateTime.fromFormat('2020-07-12 13:00', 'yyyy-MM-dd HH:mm', { zone: 'Europe/Amsterdam'});
dt.toISO() //=> "2020-07-12T13:00:00.000+02:00"
The only difference being that milliseconds are included. You can use a different formatting function if you prefer a different output.
The main benefit of Luxon is that it uses the built-in time zone functionality provided by the ECMAScript Internationalization API, whereas Moment-Timezone bundles its own time zone data - which can be quite large.
Also, note that in your question by asking for 2020-07-12T11:00:00+02:00 you seem to be misunderstanding the ISO 8601 format. In that format, the time presented is the local time. Thus, it should be 13:00, not 11:00. The +02:00 means, "this was the offset from UTC for this local time". (It doesn't mean that you apply the offset to get the local time.)

Moment.js resolve timezone offset

I'm working in an Angular 6 front end and receive from another system time stamps which have no time zones (C# backend, DateTime). I suspect that javascript is automatically adding the local time zone to Date objects.
Example:
Receiving from backend: 2018-10-15T07:53:00.000Z
When console logging: console.log(timestamp) // Mon Oct 15 2018 09:53:00 GMT+0200
I am using moment.js and already tried moment.utc() and moment(DATE).utc(). But it still adds the local time zone especially because I have to re-transform my moment objects back to the type Date with .toDate().
How can I resolve the time zone difference and get back a utc date to work with or the same structure as received?

try to format use as per desired.
let str = '2018-10-15T07:53:00.000Z';
let moment = moment(str).utcOffset(str)
console.log(moment.format('DD/MM/YYYY HH:mm'))
<script src="https://momentjs.com/downloads/moment.js"></script>
Second Snippet (to use the date object from string)
let str = '2018-10-15T07:53:00.000Z';
let moment = moment(str).utcOffset(str);
console.log(moment.toDate())
<script src="https://momentjs.com/downloads/moment.js"></script>

Your input is UTC and will be parsed just fine. Javascript Dates have no notion of timezone! The local timezone is applied by the static methods for serializing (Date.toString(), Date.toDateString() etc.) (Console.log(Date) uses Date.toString().)
Use Date.toLocaleString([],{timeZone:"UTC"}). Forcing UTC, you will see in the output the same time as the input. Much more details are here :-)
Here it is working:
console.log(new Date('2018-10-15T07:53:00.000Z').toLocaleString([],{timeZone:'UTC'}))

Get timezone from users browser using moment(timezone).js

What is the best way to get client's timezone and convert it to some other timezone when using moment.js and moment-timezone.js
I want to find out what is clients timezone and later convert his date and time into some other timezone.
Does anybody has experience with this?

When using moment.js, use:
var tz = moment.tz.guess();
It will return an IANA time zone identifier, such as America/Los_Angeles for the US Pacific time zone.
It is documented here.
Internally, it first tries to get the time zone from the browser using the following call:
Intl.DateTimeFormat().resolvedOptions().timeZone
If you are targeting only modern browsers that support this function, and you don't need Moment-Timezone for anything else, then you can just call that directly.
If Moment-Timezone doesn't get a valid result from that function, or if that function doesn't exist, then it will "guess" the time zone by testing several different dates and times against the Date object to see how it behaves. The guess is usually a good enough approximation, but not guaranteed to exactly match the time zone setting of the computer.

var timedifference = new Date().getTimezoneOffset();
This returns the difference from the clients timezone from UTC time.
You can then play around with it as you like.

All current answers provide the offset differece at current time, not at a given date.
moment(date).utcOffset() returns the time difference in minutes between browser time and UTC at the date passed as argument (or today, if no date passed).
Here's a function to parse correct offset at the picked date:
function getUtcOffset(date) {
return moment(date)
.subtract(
moment(date).utcOffset(),
'minutes')
.utc()
}

Using Moment library, see their website -> https://momentjs.com/timezone/docs/#/using-timezones/converting-to-zone/
i notice they also user their own library in their website, so you can have a try using the browser console before installing it
moment().tz(String);
The moment#tz mutator will change the time zone and update the offset.
moment("2013-11-18").tz("America/Toronto").format('Z'); // -05:00
moment("2013-11-18").tz("Europe/Berlin").format('Z'); // +01:00
This information is used consistently in other operations, like calculating the start of the day.
var m = moment.tz("2013-11-18 11:55", "America/Toronto");
m.format(); // 2013-11-18T11:55:00-05:00
m.startOf("day").format(); // 2013-11-18T00:00:00-05:00
m.tz("Europe/Berlin").format(); // 2013-11-18T06:00:00+01:00
m.startOf("day").format(); // 2013-11-18T00:00:00+01:00
Without an argument, moment#tz returns:
the time zone name assigned to the moment instance or
undefined if a time zone has not been set.
var m = moment.tz("2013-11-18 11:55", "America/Toronto");
m.tz(); // America/Toronto
var m = moment.tz("2013-11-18 11:55");
m.tz() === undefined; // true

You can also get your wanted time using the following JS code:
new Date(`${post.data.created_at} GMT+0200`)
In this example, my received dates were in GMT+0200 timezone. Instead of it can be every single timezone. And the returned data will be the date in your timezone. Hope this will help anyone to save time

if the user's timezone is all you wanted then
const localtz = moment.tz.guess() // returns user's timezone
Additionally if you wanted to use it then the best way to convert a timestamp to user's timezone is
const time = moment.tz(response.timestamp)
const localtz = moment.tz.guess() // user's timezone
const date = time.clone().tz(localtz) // convert time to user's timezone
here localtz is the user's timezone and using it we can convert the timestamp to user's local time

First, you can find out the clients time zone using the following
let zoneVal = moment().tz(Intl.DateTimeFormat().resolvedOptions().timeZone).format('Z')
it will return you the GMT zone format for example +5:30 (colombo/srilanka & Delhi/India) or +6:00(Dhaka Bangladesh) depending on the region you are in.
secondly,
if you want to find out the time of a particular time zone , then do the following
moment.tz("Asia/Dhaka").format()
which will return you the time zone value in ISO format of Dhaka.

Using moment timezone you can get easily your local date-time
moment().utcOffset(0, true).format()