DateTime in UTC not converting to Local

Question

I'm receiving a DateTime response from API that's sets the timezone to UTC.

But when I try to convert the received data using toLocal() it doesn't convert.

my local time is HKT

here's my code.

    //TIME DIFFERENCE
  getNotificationDate(DateTime date) {
    date = date.toUtc();
    final convertedDate = date.toLocal();

    final dateNow = DateTime.now();
    print('TIMENOW: ' + dateNow.toString());
    print('TIMENOTIFC: ' + convertedDate.toString());
    final difference = dateNow.difference(convertedDate);
    print('DIFFERENCE: ' + difference.toString());
    return getDurationFormat(difference);
  }

EDIT:

date is the DateTime I'm receiving from the API. which is in UTC timezone.

I used print('TIMEZONENAME: ' + date.timeZoneName; and it automatically sets the timezone to HKT. that's why it does nothing when I try to use date.toLocal()

What do you mean that it "doesn't convert"? Is the result not in local time (e.g., according to `isUtc`)? Is the time for it not correct? What output did you *expect* for your example program? — lrn, Oct 10 '19 at 14:50
for example, my current `local time` is **11:00 PM**. I'm now sending **11:00 PM** to the API. Now, my **11:00 PM** is being converted by the backend to `UTC` which would then become **3:08 pm** because the backend's `DateTime` is set to `UTC` by default. Now I will navigate to a page wherein I'm getting that `DateTime` that I just sent. I thought that by default, flutter would detect that `DateTime's` timezone but I was wrong. flutter automatically sets the incoming `DateTime` to my `Local` Timezone. — Gentle, Oct 10 '19 at 15:13
**P.S.** I'm not including my `local time` as a parameter when calling a `POST` request. it would simply be `created_at` at the backends side. — Gentle, Oct 10 '19 at 15:17
Dart `DateTime` only supports two time zones - UTC and "local". If you get an incoming time and you create a `DateTime` object for it, it will be in one of those two time zones. The incoming "time" is probably a string, so I assume you parse it. If that string contains, say, a `+02:00` time-zone marker then it is parsed as UTC by subtracting the time-zone offset from the parsed date. If it has no time-zone marker (no "+02" and no "Z") then it is interpreted as a local time. — lrn, Oct 11 '19 at 06:05
unfortunately it doesn't have `+02` or `Z`. will there be a way to change that after I receive it? — Gentle, Oct 11 '19 at 14:03
If you get the string, you can add something to it, like "Z", but that will make it be interpreted as a UTC time, not the local-time of the sender. If you get the `DateTime` object, you probably have to create a new object from that, say by doing toString, adding "Z" and parsing it again. If you *know* the time zone of the server, say UTC+3, you can add `+03:00` after the string and get the UTC-time corresponding to that moment in time — lrn, Oct 12 '19 at 20:40
Did you finally found something working ? I have same problem — Jason Simard, Oct 11 '20 at 15:54
@Gentle Can you please mark as an accepted answer so that we can save others time? :) — Aanal Shah, Jan 25 '21 at 07:30

score 74 · Answer 1 · answered Feb 12 '20 at 13:00

74

Flutter gave us the easiest way to convert it. You just need to pass utc: true while parsing your date.

var dateTime = DateFormat("yyyy-MM-dd HH:mm:ss").parse(dateUtc, true);
var dateLocal = dateTime.toLocal();

Input:

Assume my TimeZone : +05:30

UTC Date -> 2020-02-12 23:57:02.000

Output:

Local Date -> 2020-02-12 18:27:02.019660

answered Feb 12 '20 at 13:00

Aanal Shah

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2
20
30

Hi, this isn't working when I pass a date like this - 2020-08-15T05:01:31Z, which is a valid UTC date. – Varundroid Aug 30 '20 at 03:40
@Varundroid Have you tried with parsing with "yyyy-MM-ddTHH:mm:ssZ"? – Aanal Shah Sep 04 '20 at 06:19
2

@Varundroid like, var dateTime = DateFormat("yyyy-MM-ddTHH:mm:ssZ").parse("2020-08-15T05:01:31Z", true); – Aanal Shah Sep 04 '20 at 08:16
This works well but DateFormat is from the intl package – Sludge Dec 03 '20 at 18:19
Is there a way to add it at one place and make useable for all DateTime in the app? – Ahmad Khan Nov 02 '22 at 11:50
@AhmadKhan In that case, you can create a dynamic function. – Aanal Shah Nov 07 '22 at 13:30
What will be string pattern for this '2022-01-01T00:00:00+00:00' ? I don't understand the last four 0 part.. – Md. Sulayman Nov 29 '22 at 15:09
@Md.Sulayman I assume that is the timezone. eg +05:30 GMT – Aanal Shah Nov 30 '22 at 08:53

score 21 · Answer 2 · answered Oct 10 '19 at 12:05

21

// you have time in utc
var dateUtc = DateTime.now().toUtc();
print("dateUtc: $dateUtc"); // 2019-10-10 12:05:01

// convert it to local
var dateLocal = dateUtc.toLocal();
print("local: $dateLocal"); // 2019-10-10 14:05:01

Can you see the difference in hours, in utc it is 12 and locally it is 14.

answered Oct 10 '19 at 12:05

CopsOnRoad

237,138
77
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440

this code returns same dates and hour. How can I check my locale? – Giacomo M Aug 10 '20 at 13:23
@GiacomoM The code doesn't return same dates and hour, I showed the output in print format, you can see there is a time difference of GMT +2 (my local time zone). – CopsOnRoad Aug 10 '20 at 13:28
I mean, I tried in my project and I get same hour :( I do not know why – Giacomo M Aug 10 '20 at 13:33
@GiacomoM What's your time zone? – CopsOnRoad Aug 10 '20 at 13:33
It is Europe/Rome – Giacomo M Aug 10 '20 at 13:39
@GiacomoM I too have +2 time zone. Not sure why the code didn't work. – CopsOnRoad Aug 10 '20 at 13:42
I get this: `dateUtc: 2020-08-10 13:44:25.982856Z`, `local: 2020-08-10 13:44:25.982856`. As you can see the Z disappeared, but the hours are the same – Giacomo M Aug 10 '20 at 13:45
Thanks! This was perfect and simple. toLocal() – Eradicatore Dec 20 '22 at 01:48

score 8 · Answer 3 · answered Nov 22 '21 at 08:17

8

Firstly, convert your Sting to DateTime.

> DateTime dateTime = DateTime.parse(json['pickUpTime']);

Secondly, add timeZoneOffSet to your converted date time it will convert utc to your local time.

> dateTime = dateTime.add(DateTime.parse(json['pickUpTime']).timeZoneOffset);

Final Code

DateTime dateTime = DateTime.parse(json['pickUpTime']);
dateTime = dateTime.add(DateTime.parse(json['pickUpTime']).timeZoneOffset);

answered Nov 22 '21 at 08:17

Ahmad hassan

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4
14

1

all the advices with the DateFormat and toLocal or toUtc methods were not working for me. Yours did the trick. Thanks! – Christian X Apr 30 '22 at 22:19

score 7 · Answer 4 · answered Jan 11 '23 at 18:45

7

Two solutions I implemented

var date = DateFormat("yyyy-MM-ddTHH:mm:ss").parse(json, true);
var dateLocal  = date.toLocal();

Other solutions add "Z" You need to indicate a timezone to DateTime.parse, otherwise it assumes local time. From the dartdoc:

var date = DateTime.parse("${dateString}Z").toLocal();
var dateFormat = date2.toLocal();

answered Jan 11 '23 at 18:45

Ema

71
1
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Adding .toLocal() worked for me. Thank you – Manbus Sep 01 '23 at 16:58

Ahmad Aghazadeh · Answer 5 · 2019-10-10T18:00:24.360

3

You can try this code:

getNotificationDate(DateTime date) {
    date = DateTime.utc(date.year,date.month,date.day,date.hour,date.minute,date.second);;
    final convertedDate = date.toLocal();

    final dateNow = DateTime.now();
    print('TIMENOW: ' + dateNow.toString());
    print('TIMENOTIFC: ' + convertedDate.toString());
    final difference = dateNow.difference(convertedDate);
    print('DIFFERENCE: ' + difference.toString());
    return getDurationFormat(difference);
  }

edited Oct 10 '19 at 18:00

answered Oct 10 '19 at 12:12

Ahmad Aghazadeh

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1

`time` was already in local, so what's the benefit of changing it to `utc` and then back to `local`? – CopsOnRoad Oct 10 '19 at 12:14

score 3 · Answer 6 · answered Dec 22 '21 at 05:37

I've done something like this.

String dateTimeFormatter(String dateTime, {String? format}) {
  return DateFormat(format ?? 'yyyy/MM/dd, hh:mm a')
      .format(DateTime.parse(dateTime).toLocal())
      .toString();
}

just pass the format which you want to display in your app.

score 2 · Answer 7 · answered Nov 19 '20 at 06:43

2

For those who parsing TimeStamp from Firestore.

*sentAt is Timestamp

String timeToDate = widget.sentAt.toDate().toString();
    var dateTime = DateFormat("yyyy-MM-dd HH:mm:ss").parse(timeToDate, true);
    var dateLocal = dateTime.toLocal();

answered Nov 19 '20 at 06:43

Hamdam Muqimov

319
2
7

score 2 · Answer 8 · answered Jul 20 '21 at 19:45

If somebody needs to parse a UTC timestamp in isoformat, for example something like this:

>>> from datetime import datetime
>>> datetime.utcnow().format()
'2021-07-20T19:35:19.769891'

Then you can parse this and convert this to local time by

DateTime parseDatetimeFromUtc({required String isoFormattedString}){
  var dateTime = DateTime.parse(isoFormattedString + '+00:00');
  return dateTime.toLocal();
}

The '+00:00' is append here as the timezone information part which I do not send over my API to save some bytes. Maybe this helps someone who is in the same situation.

Of course you do not need this hardcoded suffix if you use a timezone aware timestamp in your backend:

>>> from datetime import datetime, timezone
>>> datetime.now(timezone.utc).isoformat()
'2021-07-20T19:42:36.538195+00:00'

score 1 · Answer 9 · answered Dec 23 '22 at 13:39

I tried several examples and forums, but it kept getting me the incorrect date time for my zone, The only way I made it work correctly was by using the GMT package

var nowLocal = DateTime.now();
print("toUtc: ${nowLocal.toUtc()}");
print("toLocalDateTime ${nowLocal.toLocalDateTime()}");
print("toLocal ${nowLocal.toLocal()}");
print("toIso8601String ${nowLocal.toIso8601String()}");
final timeZoneOffsetInHours = DateTime.now().timeZoneOffset.inHours;
final nowGMT = await GMT.now();
print("GMT: $nowGMT");
final nowActual = nowGMT?.add(Duration(hours: timeZoneOffsetInHours));
print("nowActual $nowActual");

score 0 · Answer 10 · edited Apr 16 '21 at 10:19

this is how i converted to my required time .which was showing as

I/flutter ( 5709): 16 Apr 08:30 PM 2021

when using the

var date=DateFormat("dd MMM hh:mm a y").format(DateTime.fromMillisecondsSinceEpoch(start*1000));
      print(date);

but after using this code i got my right time

var date=DateFormat("dd MMM hh:mm a y").format(DateTime.fromMillisecondsSinceEpoch(start*1000).toUtc());
      print(date);

which is

I/flutter ( 5709): 16 Apr 03:00 PM 2021

score -1 · Answer 11 · answered Nov 12 '20 at 18:06

Install intl package from pub.dev

add following line :

import 'package:intl/intl.dart';

You can make an extension like below so it will be very helpful and easy to use anywhere in a whole project.

//just make sure you have passed the right date format of utc("yyyy-MM-dd HH:mm:ss"). I have passed by default my format.

//for example
// 2020-11-25 24:12:36 -> "yyyy-MM-dd HH:mm:ss"
DateTime localDate=utcDateTime.toLocalDateTime();


//for different formats you can pass your own dateFormat for utcDate like below:
// 20-11-25 24:12:36 -> "yy-MM-dd HH:mm:ss"
DateTime localDate=utcDateTime.toLocalDateTime("yy-MM-dd HH:mm:ss");

extension DateTimeExtension on DateTime {
  DateTime toLocalDateTime({String format = "yyyy-MM-dd HH:mm:ss"}) {
    var dateTime = DateFormat(format).parse(this.toString(), true);
    return dateTime.toLocal();
  }
}

score -2 · Answer 12 · answered Apr 07 '22 at 10:43

-2

convert utc number to DateTime:

  DateTime utcToDateTime(int utc) {
    return DateTime(1970, 1, 1).add(Duration(seconds: utc));
  }

  //test
  DateTime d = utcToDateTime(1649297709);
  print(d);

answered Apr 07 '22 at 10:43

user6130977

1
2

DateTime in UTC not converting to Local

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