Day of a Gregorian Month.
assert(DateTime(Date(1999, 7, 6), TimeOfDay(9, 7, 5)).day == 6); assert(DateTime(Date(2010, 10, 4), TimeOfDay(0, 0, 30)).day == 4); assert(DateTime(Date(-7, 4, 5), TimeOfDay(7, 45, 2)).day == 5);
See Implementation
Day of a Gregorian Month.