Quote Originally Posted by Anova View Post
This is the full list of server reset times.

At those times, the system automatically checks how many players are online. If there is over a certain amount of active players, it closes off registration on that server.
Actually, those times are just when the Lodestone website updates its list of which servers are open or closed. The servers themselves are continuously updated and their actual open or closed state can change minute by minute as people log in and log out.

I'm not sure what the threshold number is, but the logic basically says that if more than X number of players are currently logged into the server, then you can't make a new character there. If enough of those people log out for the total to drop below the lockout threshold, then character creation is opened up again.