Modern Python Standard Library Cookbook

How to do it...

Go through these steps:

1. To approach this problem, we are going to actually generate all the month days that match the requested weekday:

import datetime

def monthweekdays(month, weekday):
    now = datetime.datetime.utcnow()
    d = now.replace(day=1, month=month, hour=0, minute=0, second=0,                     microsecond=0)
    days = []
    while d.month == month:
        if d.isoweekday() == weekday:
            days.append(d)
        d += datetime.timedelta(days=1)
    return days

2. Then, once we have a list of those, grabbing the n^th day is just a matter of indexing the resulting list. For example, to grab the Mondays from March:

>>> monthweekdays(3, 1)
[datetime.datetime(2018, 3, 5, 0, 0),  datetime.datetime(2018, 3, 12, 0, 0), 
 datetime.datetime(2018, 3, 19, 0, 0),  datetime.datetime(2018, ...