This page gives a estimate of the starting times of the public events. For those of you who can't figure out what the x means before the number it just means that they can happen any hour of the day. The numbers after the x are the times of the hour where the events can happen. I don't think these are guaranteed times but i tried a few and it worked for me. This list should come in handy when you need to do the daily public event or when you get the bounty and you could also farm for loot.