While I think the timing is awkward for euro players they constitute a small fraction of the userbase.

I do however think some things can be done to limit the horde shields and modests until the last minute and blitz routine that everyone seems to do currently.

If you limit the number of cards that can be played in an hour it becomes a much more strategic game. Another idea would be to keep the time roughly the same but to have it end at a random time during that hour. You could hide the precise end time and people would need to rush a bit earlier or risk losing access to cards.