flutter HTTP date strings with DateFormat - flutter

Question

intl: ^0.16.1
Can't seem to parse HTTP header date field with flutter DateFormat/HttpDate
here is what I tried:
var date = HttpDate.parse("Thu, 11 Feb 2021 10:53:15 +0200");
return error:
Invalid HTTP date Thu, 11 Feb 2021 10:53:15 +0200
Note: the string was received by package:googleapis/gmail/v1.dart
final zFormatDateEmailRFC2822 = DateFormat("EEE, d MMM yyyy HH:mm:ss Z");
var date = zFormatDateEmailRFC2822.parse("Thu, 11 Feb 2021 10:53:15 +0200");
return error:
Trying to read EEE from Thu, 11 Feb 2021 10:53:15 +0200 at position 0
The following is an example from https://api.flutter.dev/flutter/intl/DateFormat-class.html
final fmt = DateFormat('EEE, MMM d, ''yy');
var date = fmt.parse("Wed, Jul 10, '96");
return error:
Trying to read EEE from Wed, Jul 10, '96 at position 0
final fmt = DateFormat("d MMM yyyy");
var date = fmt.parse("11 Feb 2021");
return error:
Trying to read MMM from 11 Feb 2021 at position 3
final fmt = DateFormat("MMM");
var date = fmt.parse("Feb");
return error:
Trying to read LLL from Feb at position 0
The only thing that works for me is:
var dateStr = "Thu, 11 Feb 2021 10:53:15 +0200";
RegExp regExp = RegExp(r"(.*, \d+ .* \d+ \d+:\d+:\d+)");
if (regExp.hasMatch(dateStr)) {
var groups = regExp.firstMatch(dateStr);
var date = HttpDate.parse(groups[1] + " GMT");
print("date $date >${HttpDate.format(date)}<");
}

Answer 1

Try it:
final fmt = DateFormat("d MMM yyyy", "en_US");
var date = fmt.parse("11 Feb 2021");

Answer 2

I had to parse the email header date string
Somehow the other answers where not considering everything i needed and so i came up with the following solution which also takes care of the timezone +0200
DateFormat('E, d MMM yyyy hh:mm:ss Z', 'en_US').parse(DATE_STRING);
Input String : Wed, 18 Aug 2021 09:00:43 +0200
DateTime.toISo8601String() => 2021-08-18T09:00:43.000
DateTime.toUTC().toString() => 2021-08-18 07:00:43.000Z
If you want to learn more about the patterns please have a look at DateFormat