final DateTime fourHoursFromNow = DateTime.now() + Duration(hours: 4);

dependencies:
  time: "^1.3.0"

import 'package:time/time.dart';

final Duration tenMinutes = 10.minutes;
final Duration oneHourThirtyMinutes = 1.5.hours;
final DateTime afterTenMinutes = DateTime.now() + 10.minutes;
final Duration tenMinutesAndSome = 10.minutes + 15.seconds;
final int tenMinutesInSeconds = 10.minutes.inSeconds;
final DateTime tenMinutesFromNow = 10.minutes.fromNow;

final Duration interval = 10.minutes + 15.seconds - 3.minutes + 2.hours;
final Duration doubled = interval * 2;

final DateTime oneHourAfter = DateTime() + 1.hours;

final int twoMinutesInSeconds = 2.minutes.inSeconds;

final DateTime timeInFuture = 5.minutes.fromNow;
final DateTime timeInPast = 5.minutes.ago;

final DateTime start = DateTime(2019, 12, 2);
final DateTime end = start + 1.weeks;
final DateTime tuesday = start.to(end).firstWhere((date) => date.weekday == DateTime.tuesday);

void doSomething() async {
  await 5.seconds.delay;
  // Do the other things
}

final initial = DateTime(2019, 2, 4, 24, 50, 45, 1, 1);
final expected = initial.copyWith(
  year: 2021,
  month: 10,
  day: 28,
  hour: 12,
  minute: 45,
  second: 10,
  millisecond: 0,
  microsecond: 12,
);