There is problem with events. US time and European time is different but events are announced using US time. For players in EU it can make headaches. Why? I did played last 2 events, made required time but part of the time didn't fit in events time.
Solution 1 - Better but harder
The best solutions for this is use Event tab located in "My Info/My Challenges/"
Simply add there time to event start and event end and progress. Users will have good place to search for events, event progress will be exact. And it will reduce tickets count.
Solution 2 - Worse but faster
Add something like table to event announcement With event end time. Not like it is done with this: http://ava.aeriagames.com/news/64121/thanksgiving-holiday-events
Its useless cause this event has different requirements for different day,.