Question

Given a date, how do you know the weekday position in the month (ex: third tuesday of the month) and how do you get the date for the same weekday for the next month (ex: third tuesday of the month+1)?

Answer 1

In the examples below, d is a datetime.date object.

To get the “index” of the day within the current month, use

def weekday_index(d):
    return (d.day + 6) // 7

This formula will work independent of what weekday the date actually is. To get the day wich is the same weekday with the same weekday index within the next month, the simplest way seems to be

d_next = d + datetime.timedelta(weeks=4)
if weekday_index(d_next) < weekday_index(d):
    d_next += datetime.timedelta(weeks=1)

This uses the fact the the date you are looking for is either 4 weeks or 5 weeks after d.