I don't think that honey ever really goes "bad" any more than sugar does. It does change, getting more of the HMF over time which while bad for bees doesn't affect us.http://www.airborne.co.nz/HMF.html
I don't worry about it. If it is around I'll eat it, but thankfully my own is usally gone in less than a year so it isn't a worry.
Haven't had a chance to try ancient Egyptian honey, and probably won't be around to try my honey in 2000 years, so that don't bother me much either.