Performance Dropping in Late Times

I play Atomic, but that's not the problem.
I saw that when I play in late times (after 22.00) , my performance drops about 200 points.
I think there must be other players who can't play in late times.
Yesterday I played about 40 minutes of the Weekly Atomic Arena, and I dropped to 2150 from 2279. Lost to 1600s 1800s etc.

How do you deal with this situation ?
( You dont have to play atomic to answer this)

Chess is all about concentration. If it is late, then fatigue kicks in. Grandmasters usually plan their day such that their tournament game falls in the middle of it, not at the end. They schedule their sleep accordingly.