Setting this hilariously stupid debate aside, it really is inconvenient the week has 7 days.
We humans are creatures of habit, and like to do things on the same days every week - either because regularity helps our schedule, or simply because we're all perhaps a little OCD.
I personally wash my hair "every other day" so to keep a fixed weekly schedule I have to either miss two days in a row (not happening) or wash two in a row (which is what I do)
So I totally understand the desire to want "every other day" things on the same days of the week AND still also perfectly spaced, even though that is an impossibility.
It's just that tiniest bit unsatisfying.