Im an alt-a-holic and I can get characters made anytime in the early mornings before 10-11AM EST. I've also some friends who got in 2-3AM EST making a character, though I'd much rather wake up a bit earlier than to stay up all night. The ONLY exception i've seen for this is when the 2.4 update came out and people had logged in RIGHT after the patch was finished to buy houses and power lvl rog/nin ASAP.

Note: This is my personal experience with the times. I've been trying to make a character with a desired name supposedly not taken because it doesn't come up on Lodestone, yet I get the error that it is taken. I've been camping for a good 2-3 months now and those times are what I have experienced over the many alts I've made.