Explain what WEEK_DAYS is

[Flimm]

In config.py, you can configure WEEK_DAYS, like this:

WEEK_DAYS = (MO, TU, WE, TH, FR, SA, SU)

According to the dictionary, a week day is:

a day of the week other than Sunday or Saturday. "the weekday rush hour"

So it is confusing why you would include Saturday or Sunday here. And what is the difference between this variable and the BUSINESS_DAYS variable?