formatDateTimeToIsoWithTimezone method
Formats the DateTime as ISO with timezone: yyyy-MM-ddTHH:mm:ss+HHMM
Works without intl package.
Example:
DateTime.utc(2023, 5, 10, 14, 30).formatDateTimeToIsoWithTimezone();
// "2023-05-10T14:30:00+0000"
DateTime(2023, 5, 10, 14, 30).formatDateTimeToIsoWithTimezone();
// "2023-05-10T14:30:00+0200"
Implementation
String formatDateTimeToIsoWithTimezone() {
String twoDigits(int n) => n.toString().padLeft(2, '0');
final y = year;
final m = twoDigits(month);
final d = twoDigits(day);
final h = twoDigits(hour);
final min = twoDigits(minute);
final s = twoDigits(second);
return '$y-$m-${d}T$h:$min:$s';
}