Any time is fine.

It's usually nice and calm at night, though, but activity is also pretty low so it can be a tad boring, but if I ever wake up early then it's good to just browse around and see what I missed while I was sleeping and just comment all over while most are still snoozing.
But hint to trolls and attention-seekers: Around 3:15am to 7am EST or so are the best times to put up WP-worthy threads. Most mods are sleeping or simply not active during those times, so if you want to put up a bad thread and have it not automatically get closed - go for it!
