Antonica & Commonlands Public Quests

Can someone do me a favor and remind me how the public quests work and how long the timers are?

I forget the timers, but basically when it starts successive waves of progressively more powerful enemies spawn and attack anyone in the area. If they aren't defeated in x amount of time, they depop and the event respawns them at a lower difficulty tier. Every time the event lowers the difficulty, the rewards lessen.

Once per hour I believe - I think it was on the hour, but it has been awhile.