Being a mod is a volunteer position and as such many in-game mods have other lives they must live, aside from FH. Many of them need to get up first thing in the morning to go to school, or work. I must say it is a little unreasonable to ask them so sacrifice precious sleep for FH, as they put so much time and effort into it already, and it should never affect their regular lives offline by depriving them of sleep.
However I do believe it should be considered getting mods in different time zones, so that there may be at least one mod awake and online at all times, however with FH still growing and developing it makes it even more tricky to hire and train new mods, when there is still so much going on.
In the mean-time you'll just have to do what Kyugima suggested, although I agree with what Tristam said as well.
The admins are aware of this problem, and are as much frustrated as everyone else. I'm certain everyone is doing their best to solve this problem and we'll just need to give it some time...
which sucks.