Because of family obligations I mostly play at night. Anywhere from 6-8pm and on. Also with my stream I see a bigger audience at during those times. I do think though that if I didn't have a family and was playing full time I'd probably play during the day. I've also heard that 3rd shift type hours are very profitable because there are a lot of buzzed/drunk players but it can also be a minefield for the same reasons.
to me it depends. because i have a daughter. so during her naos its an awesome time but usually when i can focus only on poker. that is when i play my best
The best time for me -- when I am ready to play (anytime). I just need to be ready for the game: eat well, sleep well, have no urgent problems to solve...
Tables tend to be a lot more fun at night. Depends on where though. Online and indian casinos I feel are only good at night. Vegas is decent any time of day as long as the city is busy.