just watch the clock in the tower.
there is only one time.
ah2, iirc, had time skip at night, and maybe blocks of the day, i never figured it quite out. time did move so a minute was a minute, and gaps were made up with clock jumps.
possibly why missions could not be run beyond full daylight, because of AH2 time shift at night.
AH3 clock winds around like monday night sleep.