DateTime.utc constructor

DateTime.utc(int year, [ int month = 1, int day = 1, int hour = 0, int minute = 0, int second = 0, int millisecond = 0, int microsecond = 0 ])

Constructs a DateTime instance specified in the UTC time zone.

var moonLanding = new DateTime.utc(1969, 7, 20, 20, 18, 04);

When dealing with dates or historic events prefer to use UTC DateTimes, since they are unaffected by daylight-saving changes and are unaffected by the local timezone.

Implementation 

DateTime.utc(int year,
    [int month = 1,
    int day = 1,
    int hour = 0,
    int minute = 0,
    int second = 0,
    int millisecond = 0,
    int microsecond = 0])
    : this._internal(year, month, day, hour, minute, second, millisecond,
          microsecond, true);