For what it's worth, W and I switch our care of D on Friday's after day care.
She drops her in the morning and I pick her up at days end to start my week.

One full week each

I changed it from Sundays for a few reasons-
1) It doesn't trash long weekends
2)We START the weekends with D to get Quality time
3)I don't have to interact with W.

Just my set up.