use datetime in flutter code example

Example 1: flutter get current date

import 'package:intl/intl.dart';

main() {
  static final DateTime now = DateTime.now();
  static final DateFormat formatter = DateFormat('yyyy-MM-dd');
  final String formatted = formatter.format(now);
  print(formatted); // something like 2013-04-20
}
// https://pub.dev/documentation/intl/latest/intl/DateFormat-class.html

Example 2: flutter date with timezone

/// converts [date] into the following format: `2020-09-16T11:55:01.802248+01:00`
static String formatISOTime(DateTime date) {
  var duration = date.timeZoneOffset;
  if (duration.isNegative)
  	return (date.toIso8601String() + "-${duration.inHours.toString().padLeft(2, '0')}:${(duration.inMinutes - (duration.inHours * 60)).toString().padLeft(2, '0')}");
  else
  	return (date.toIso8601String() + "+${duration.inHours.toString().padLeft(2, '0')}:${(duration.inMinutes - (duration.inHours * 60)).toString().padLeft(2, '0')}");
}