DateTime in UTC not converting to Local - datetime

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()

Answer 1

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

Answer 2

// 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.

Answer 3

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);

Answer 4

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);
}

Answer 5

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.

Answer 6

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'

Answer 7

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();

Answer 8

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

Answer 9

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");

Answer 10

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();

Answer 11

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();
}
}

Answer 12

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);