Python event scheduling

Question

I'm working on a Python (Tkinter) app for an irrigation timer. The user enters the days of the week for each valve using the following screen:

I'm able to process the data from the checkboxes to get the days of the week:

['Sunday', 'Tuesday', 'Friday', 'Monday', 'Thursday', 'Monday', 'Wednesday', 'Friday', 'Wednesday', 'Saturday'].

But, I need to know how many days are in between each "on" day. For example, for Valve 1, 2 days between Sunday and Tuesday and three days from Tuesday to Friday, but I don't know how to get the number days from the Friday to the next Sunday. Can anyone suggest an approach? Thanks in advance for any help!

Answer 1

def daysDifference(day1:int, day2:int):
    """
    day1: The index of the first day.
    day2: The index of the second day.
    Returns the time from one to the next.
    """
    if day1 <= day2:
        return day2 - day1
    else:
        return 7 - day1 + day2

I'm pretty sure this will work.