Yeah, gonna go with Tuesday morning as well!
I've updated on all days, but noticed a slightly larger traffic on Tuesdays.
i think it might have to do with Mondays being tired after the weekend, Tuesday's like a back to normal kind of day, Wednesdays are in the middle of the week, so people are probably doing other things. Thursday's good too but not as great as Tuesdays.
Fridays, Saturdays and Sundays: People are often away during those times, so it's bound to be less traffic those days.
But other days might work better for you! If you're able to, you can try out and see what'll fit (which is what I've done, and Tuesdays were at the top!).