Kinda depends which stakes your play. I assume not micro, so whenever you have more weak players higher winrate you suppose to have. Feels like not much data to analyze, even month to month different.

I would suggest take day off when you want or feel comfortable(socialize with family and friends, other activities, and not look too much into losing 1bb because it is start of the week,lol). I know some guys who take day off Monday or Tuesday because more regs ratio than in weekend.

When playing HS or games really struggle to start, well time for good schedule.

The most profitable day is the day you play your best game