031_dates.dart

// ignore_for_file: unused_local_variable

void foo1() {
// Get the current date and time.
  var now = DateTime.now();

// Create a new DateTime with the local time zone.
  var y2k = DateTime(2000); // January 1, 2000

// Specify the month and day.
  y2k = DateTime(2000, 1, 2); // January 2, 2000

// Specify the date as a UTC time.
  y2k = DateTime.utc(2000); // 1/1/2000, UTC

// Specify a date and time in ms since the Unix epoch.
  y2k = DateTime.fromMillisecondsSinceEpoch(946684800000, isUtc: true);

// Parse an ISO 8601 date in the UTC time zone.
  y2k = DateTime.parse('2000-01-01T00:00:00Z');

// Create a new DateTime from an existing one, adjusting just some properties:
  var sameTimeLastYear = now.copyWith(year: now.year - 1);
}

void foo2() {
// 1/1/2000, UTC
  var y2k = DateTime.utc(2000);
  assert(y2k.millisecondsSinceEpoch == 946684800000);

// 1/1/1970, UTC
  var unixEpoch = DateTime.utc(1970);
  assert(unixEpoch.millisecondsSinceEpoch == 0);
}

void foo3() {
  var y2k = DateTime.utc(2000);

// Add one year.
  var y2001 = y2k.add(const Duration(days: 366));
  assert(y2001.year == 2001);

// Subtract 30 days.
  var december2000 = y2001.subtract(const Duration(days: 30));
  assert(december2000.year == 2000);
  assert(december2000.month == 12);

// Calculate the difference between two dates.
// Returns a Duration object.
  var duration = y2001.difference(y2k);
  assert(duration.inDays == 366); // y2k was a leap year.
}

void main(List<String> args) {}