The day / night cycle would not have gotten out of whack that much in that short of a period of time, and most of the US airplanes do have radar. Of course, how you target a wooden ship at night with radar... well that's another story... But yes, a lot of the US planes do fly at night, and a portion of the Japanese planes do also.
As Front Runner found the cycles, the "world" itself and the night / day cycle were two separate entities, apparently run by different timers in the game. He has his nVidia Inspector settings in this post:
Post 66 in Base Time 2018 thread
Which do seem to help keep things in sync, including when doing various real time and tc settings.
