deltatime calculation

[snippsat]

You most first parse the date input with strptime() then add 5 weeks.

>>> from datetime import datetime
>>> 
>>> order_date = '2018-10-11'
>>> delivery_date = 5
>>> dt = datetime.strptime(order_date, '%Y-%m-%d')
>>> dt
datetime.datetime(2018, 10, 11, 0, 0)
>>> # Now can add weeks
>>> dt + timedelta(weeks=delivery_date)
datetime.datetime(2018, 11, 15, 0, 0)