We Keep Coding

How to convert into Format 2016-10-19T08:00:00Z with momentjs

in a project we are using momentjs with date. And from backend we become the date in the following format: 2016-10-19T08:00:00Z (don't ask me why...)
Now we are setting a new date in frontend from some selectboxes. And I am trying to convert this in the same format:
const date = '25.03.2021';
const hour = '13';
const minute = '45'; // this 3 values come from value of selectboxes
const rawDate = moment(date).hour(hour).minute(minute);
// trying to convert to 2021-03-25T13:45:00Z
rawDate.format(); // output: 2021-03-25T13:45:00+00:00
rawDate.format('DD.MM.YYYY hh:mm:ss'); // output: 03.01.2022 08:00:00
rawDate.format('DD.MM.YYYY hh:mm:ss z'); // output: 03.01.2022 08:00:00 UTC
rawDate.format('DD.MM.YYYY hh:mm:ss Z'); // output: 03.01.2022 08:00:00 +00:00
rawDate.toISOString(); // output: 2022-01-03T08:00:00.000Z
I know I could probably just use format() or toISOString() and slice/replace the last bit. But I like to know is there a way without any string concat/manipulation?

You could use moment.utc() to ensure your date is in UTC, then use .format() with the format string DD-MM-YYYYTHH:mm:ss[Z].
I'd also suggest explicity defining the format you are parsing from in the moment() call, e.g. pass 'DD.MM.YYYY' as the second argument.
The reason the backend takes dates in this format is that it's a standardized way of formatting dates to make them machine-readable and consistent (ISO 8601)
const date = '25.03.2021';
const hour = '13';
const minute = '45';
// Raw date will be in the UTC timezone.
const rawDate = moment(date, 'DD.MM.YYYY').hour(hour).minute(minute).utc();
console.log(rawDate.format('DD-MM-YYYYTHH:mm:ss[Z]'));
<script src="https://momentjs.com/downloads/moment.js"></script>

You can try convert to UTC ..?
i.e. Do you intend to make use of a UTC date/time..?
const date = '2021-03-25';
const hour = '13';
const minute = '45'; // this 3 values come from value of selectboxes
const rawDate = moment(date).hour(hour).minute(minute);
const utc = moment.utc(rawDate);
console.log(rawDate.format('DD.MM.YYYY hh:mm:ss'));
console.log(utc.format()); //2021-03-25T11:45:00Z

Date in CET timezone to user's timezone

I have a list of list of string dates like this: '17/12/2017 19:34'. They are CET dates.
How can I transform it to the user's browser date?
I'm doing this:
const tzGuess = moment.tz.guess()
export const toTimeZone = (time) => {
const format = 'DD/MM/YYYY HH:mm'
return moment(time, format).tz(tzGuess).format(format)
}
console.log(toTimeZone('17/12/2017 19:34', tzGuess))
but how can I say to moment that the date I'm passing at first is a CET one?
Thanks!

You can use moment.tz function for parsing time string using a given timezone (e.g. 'Europe/Madrid').
The issue is: what do you mean with CET? If your input has fixed UTC+1 offset (like Central European Time), then you can use RobG's solution. If you have to consider both CET and CEST, I think that the best soution is to use moment.tz.
Here a live code sample:
const tzGuess = moment.tz.guess()
const toTimeZone = (time) => {
const format = 'DD/MM/YYYY HH:mm'
return moment.tz(time, format, 'Europe/Madrid').tz(tzGuess).format(format)
}
console.log(toTimeZone('17/12/2017 19:34', tzGuess))
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.19.4/moment.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.13/moment-timezone-with-data-2012-2022.min.js"></script>
A great resource about timezone is the timezone tag info page.

Without moment.js, parse the string to a Date, treating it as UTC, then adjust for the CET offset (+0100). You can then format it using local time values for the client:
// Parse date in format DD/MM/YYYY HH:mm
// Adjust for CET timezone
function parseCET(s) {
var b = s.split(/\D/);
// Subtract 1 from month and hour
var d = new Date(Date.UTC(b[2], b[1]-1, b[0], b[3]-1, b[4]));
return d;
}
var s = '17/12/2017 19:34';
console.log(parseCET(s).toString());
However, if the time needs to observe daylight saving (CEST) for the source time stamp, you'll need to account for that.

Moment Js UTC to Local Time

I'm trying to convert UTC time to the local time. I've been following this example from this link: http://jsfiddle.net/FLhpq/4/light/. I can't seem to get the right local output. For example, if its 10: 30 am in here, instead of getting 10:30 ill get 15: 30. Here is my code:
var date = moment.utc().format('YYYY-MM-DD HH:mm:ss');
var localTime = moment.utc(date).toDate();
localTime = moment(localTime).format('YYYY-MM-DD HH:mm:ss');
console.log("moment: " + localTime);
No matter what I do the time always comes out at UTC time. I live in Houston so I know timezone is the issue. I've followed the code in the link but can seem to get the local time. What am I doing wrong?

To convert UTC time to Local you have to use moment.local().
For more info see docs
Example:
var date = moment.utc().format('YYYY-MM-DD HH:mm:ss');
console.log(date); // 2015-09-13 03:39:27
var stillUtc = moment.utc(date).toDate();
var local = moment(stillUtc).local().format('YYYY-MM-DD HH:mm:ss');
console.log(local); // 2015-09-13 09:39:27
Demo:
var date = moment.utc().format();
console.log(date, "- now in UTC");
var local = moment.utc(date).local().format();
console.log(local, "- UTC now to local");
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.min.js"></script>

Try this:
let utcTime = "2017-02-02 08:00:13";
var local_date= moment.utc(utcTime).local().format('YYYY-MM-DD HH:mm:ss');

let utcTime = "2017-02-02 08:00:13.567";
var offset = moment().utcOffset();
var localText = moment.utc(utcTime).utcOffset(offset).format("L LT");
Try this JsFiddle

To convert UTC to local time
let UTC = moment.utc()
let local = moment(UTC).local()
Or you want directly get the local time
let local = moment()
var UTC = moment.utc()
console.log(UTC.format()); // UTC time
var cLocal = UTC.local()
console.log(cLocal.format()); // Convert UTC time
var local = moment();
console.log(local.format()); // Local time
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment.min.js"></script>

Note: please update the date format accordingly.
Format Date
__formatDate: function(myDate){
var ts = moment.utc(myDate);
return ts.local().format('D-MMM-Y');
}
Format Time
__formatTime: function(myDate){
var ts = moment.utc(myDate);
return ts.local().format('HH:mm');
},

This is old question I see, but I didn't really get what I was looking for. I had a UTC datetime which was formatted without timezone. So I had to do this:
let utcDatetime = '2021-05-31 10:20:00';
let localDatetime = moment(utcDatetime + '+00:00').local().format('YYYY-MM-DD HH:mm:ss');

I've written this Codesandbox for a roundtrip from UTC to local time and from local time to UTC. You can change the timezone and the format. Enjoy!
Full Example on Codesandbox (DEMO):
https://codesandbox.io/s/momentjs-utc-to-local-roundtrip-foj57?file=/src/App.js

This is what worked for me, it required moment-tz as well as moment though.
const guess = moment.utc(date).tz(moment.tz.guess());
const correctTimezone = guess.format()

Here is what I do using Intl api:
let currentTimeZone = new Intl.DateTimeFormat().resolvedOptions().timeZone; // For example: Australia/Sydney
this will return a time zone name. Pass this parameter to the following function to get the time
let dateTime = new Date(date).toLocaleDateString('en-US',{ timeZone: currentTimeZone, hour12: true});
let time = new Date(date).toLocaleTimeString('en-US',{ timeZone: currentTimeZone, hour12: true});
you can also format the time with moment like this:
moment(new Date(`${dateTime} ${time}`)).format('YYYY-MM-DD[T]HH:mm:ss');

I've created one function which converts all the timezones into local time.
Requirements:
1. npm i moment-timezone
function utcToLocal(utcdateTime, tz) {
var zone = moment.tz(tz).format("Z") // Actual zone value e:g +5:30
var zoneValue = zone.replace(/[^0-9: ]/g, "") // Zone value without + - chars
var operator = zone && zone.split("") && zone.split("")[0] === "-" ? "-" : "+" // operator for addition subtraction
var localDateTime
var hours = zoneValue.split(":")[0]
var minutes = zoneValue.split(":")[1]
if (operator === "-") {
localDateTime = moment(utcdateTime).subtract(hours, "hours").subtract(minutes, "minutes").format("YYYY-MM-DD HH:mm:ss")
} else if (operator) {
localDateTime = moment(utcdateTime).add(hours, "hours").add(minutes, "minutes").format("YYYY-MM-DD HH:mm:ss")
} else {
localDateTime = "Invalid Timezone Operator"
}
return localDateTime
}
utcToLocal("2019-11-14 07:15:37", "Asia/Kolkata")
//Returns "2019-11-14 12:45:37"

from unix timestamp to datetime

I have something like /Date(1370001284000+0200)/ as timestamp. I guess it is a unix date, isn't it? How can I convert this to a date like this: 31.05.2013 13:54:44
I tried THIS converter for 1370001284 and it gives the right date. So it is in seconds.
But I still get the wrong date for:
var substring = unix_timestamp.replace("/Date(", "");
substring = substring.replace("000+0200)/", "");
var date = new Date();
date.setSeconds(substring);
return date;

Note my use of t.format comes from using Moment.js, it is not part of JavaScript's standard Date prototype.
A Unix timestamp is the number of seconds since 1970-01-01 00:00:00 UTC.
The presence of the +0200 means the numeric string is not a Unix timestamp as it contains timezone adjustment information. You need to handle that separately.
If your timestamp string is in milliseconds, then you can use the milliseconds constructor and Moment.js to format the date into a string:
var t = new Date( 1370001284000 );
var formatted = moment(t).format("dd.mm.yyyy hh:MM:ss");
If your timestamp string is in seconds, then use setSeconds:
var t = new Date();
t.setSeconds( 1370001284 );
var formatted = moment(t).format("dd.mm.yyyy hh:MM:ss");

Looks like you might want the ISO format so that you can retain the timezone.
var dateTime = new Date(1370001284000);
dateTime.toISOString(); // Returns "2013-05-31T11:54:44.000Z"
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toISOString

Without moment.js:
var time_to_show = 1509968436; // unix timestamp in seconds
var t = new Date(time_to_show * 1000);
var formatted = ('0' + t.getHours()).slice(-2) + ':' + ('0' + t.getMinutes()).slice(-2);
document.write(formatted);

The /Date(ms + timezone)/ is a ASP.NET syntax for JSON dates. You might want to use a library like momentjs for parsing such dates. It would come in handy if you need to manipulate or print the dates any time later.

If using react:
import Moment from 'react-moment';
Moment.globalFormat = 'D MMM YYYY';
then:
<td><Moment unix>{1370001284}</Moment></td>

Import moment js:
var fulldate = new Date(1370001284000);
var converted_date = moment(fulldate).format(");

if you're using React I found 'react-moment' library more easy to handle for Front-End related tasks, just import <Moment> component and add unix prop:
import Moment from 'react-moment'
// get date variable
const {date} = this.props
<Moment unix>{date}</Moment>

I would like to add that Using the library momentjs in javascript you can have the whole data information in an object with:
const today = moment(1557697070824.94).toObject();
You should obtain an object with this properties:
today: {
date: 15,
hours: 2,
milliseconds: 207,
minutes: 31,
months: 4
seconds: 22,
years: 2019
}
It is very useful when you have to calculate dates.

for people as dumb as myself, my date was in linux epoch
but it was a string instead of an integer, and that's why i was getting
RangeError: Date value out of bounds
so if you are getting the epoch from an api, parseInt it first
var dateTime = new Date(parseInt(1370001284000));
dateTime.toISOString();

how can change the text string to date object?

i am getting string from server and i need to covert that fetching string in to new date object.. for doing this, i tried this function, but no use, any one can help me to convert strings to date object?
my code is :
var nationZone = {
getNewYorkLocalTime : 'getTime.php?lat=40.71417&lan=74.00639',
getLondonLocalTime : 'getTime.php?lat=51.5&lan=0.1166667',
getChennaiLocalTime : 'getTime.php?lat=13.0833333&lan=80.2833333',
getBangaloreLocalTime:'getTime.php?lat=12.9833333&lan=77.5833333'
}
$.each(nationZone , function(key, value){
$.get(value, function(response){
var newdate = $(response).find('localtime').text();
if(key == "getNewYorkLocalTime"){
var newyourktime = new Date(newdate);
newyourktime.getTime()
}
});
});
but, the newyourktime is showing local time only.. any help please? as well i am getting the response from server is : 17 Nov 2011 18:09:47 - like this.

Use http://www.datejs.com/
As an example:
var newyourktime = Date.parse('2011-11-11, 11:11 AM');
alert(newyourktime.toString('dd/mm/yyyy HH:mm:ss EST'));
Check out the Datejs library documentation to meet your requirements, after your date string is parsed, you can do a lot with it.

This will try to parse the date using the client machine own local settings, which is not good.
Instead of passing it as string, pass it as the total seconds that passed since 1/1/1970 at midnight and use this number when constructing the new Date object of JavaScript.
For example pass this number: 1321614000000 and you will get November 18th 2011, 1 PM

You could use substr
day = newdate.substr(0,2);
month = newdate.substr(3,3);
year = newdate.substr(7,4);
var newyorktime = new Date(year, month, day);
Substr