dart:core

weekday property

int weekday

The day of the week MONDAY..SUNDAY.

In accordance with ISO 8601 a week starts with Monday, which has the value 1.

DateTime moonLanding = DateTime.parse("1969-07-20 20:18:00");
assert(moonLanding.weekday == 7);
assert(moonLanding.weekday == DateTime.SUNDAY);

Source

external int get weekday;