Once a day. So if it's 11:50 PM and you vote because you haven't voted yet, go ahead and vote again in ten minutes; but that vote at midnight will count as your day's vote, and you'd have to wait another day to vote again. That's pretty much how all H/H threads, if I'm not mistaken.
Heal Shinon, Hurt Vika.
But no really I never expected to see Shinon in the top five. I always thought everyone hated him. ;A; -Goes to proud corner-