Returns true if this occurs after other.
The comparison is independent of whether the time is in UTC or in the local time zone.
DateTime berlinWallFell = new DateTime(1989, 11, 9);
DateTime moonLanding = DateTime.parse("1969-07-20 20:18:00");
assert(berlinWallFell.isAfter(moonLanding) == true);
Source
bool isAfter(DateTime other) {
return _value > other._value;
}