On the weekly challenges, it's very unfair that people that are awake till the end of the challenge can get more time to collect things than the people that are sleeping like for example, you can get from N#1400 to N#3000 in one night without being able to win more stars/gems.
I think it would be nice if the challenge were ended on the same hour but by taking in consideration the timezones for all the countries, but then the results would be announced the day after.
That would mean that the challenge would start at different times too.
It would be nice if it ended near 7PM or something.
(sorry for my bad english)