Returns the week of the year during which this date falls, if weeks are understood to being on Sunday. The date must be valid. Can return 0 if the day is before the first Sunday of the year.
Return: week number
See Implementation
Returns the week of the year during which this date falls, if weeks are understood to being on Sunday. The date must be valid. Can return 0 if the day is before the first Sunday of the year.
Return: week number