Immediately went to post again, but it told me I had to wait until 11:39pm.
Fine, no problem, it was 11:38pm.
Waited 2 minutes (11:40pm) and tried again - it told me I must wait until 11:39pm. Tried again a few minutes later - same deal.
Is it possible the 'wait until' time is calculated for my local time, but enforced against the system clock, thereby making me wait something like 5-7 hours?
I believe the issue has been fixed. It actually had nothing to do with local time versus server time, but rather as a result of a "dupe check" based on rating the same person again. If you had rated Amshak and then turned around and immediately rated Barada, you wouldn't have had a problem.
Anyway, the problem has been fixed and you shouldn't get that error message again.