Monday is based on the moon, following Sunday, the day of the sun. cute idea though. I imagine the gods have different days they may favor based on their feelings or..well, demons would have natal charts for themselves, or what I should say is, based on their interests in their lives.
I wish I had the link, but the days were already said to be based on..Nordic beliefs and gods and goddesses, I think. I could be wrong.
sun, moon, and Freya come to mind, I dont remember the rest. but I've heard Nordic attributions as well as Greco-Roman attributions of certain (similar and equivalently roles deities) for the days. same role, same order.
(this doesn't mean you shouldn't celebrate Monday)