3 minutes between atempts more or less I believe,thats why its imperative one try to reach maximum tame potential with jewels need be before trying.With 120 tame and lore you can usually tame GDs on first atempt or two,thats plenty time left on honor to run outside or recall.Besides GDS i dont think youl need honor anything else wortwhile is easy enough if you nail the technique a bit.
I know it is at least 4 minutes, as I've attempted to honor myself a second time after running screaming when Honor was used up, and the system message stated "hey, doofus, you need to wait at least 4 minutes before repeated use, DUHHHH". Worded slightly differently, 'course.
I guessed 5 minutes as it was a somewhat sizable delay between running screaming out of destard, curing myself, healing myself up, and attempting to honor myself again.
In any case, not everyone can afford 120 scrolls, so if at all possible, try to get a friend to help you out. someone to cure/heal you should be plenty if you've beat it down beforehand and are at least somewhat capable of lead taming.
A reminder I've found I have to give constantly to the few less experienced in taming greaters and other heavy hitting angerers:
Don't melee the dragon. You'll lose.