Astro Galaxy - a realistic space exploration game

I don't know if there is a fundamental reason why the timer has to be 24 hours, but I would suggest making it 23 hours. Reason being, almost no one is going to be online to vote the moment the timer expires every day. That being said, every day you vote later and later, and eventually, the timer will be expiring after you rest for the day/evening. If you make it 23 hours, it gives people the chance to back petal a little bit in case that have to vote late in the day for themselves.

Arctic

It is 24 hours because most voting sites have a 24 hour timer and only let you vote once every 24 hours.