Game Clock

Game Clock vs Real Clock
The Satisfactory game time simulates a 24 hour day for each 1 hour of actual playing time (24x real-time). Both the game clock and Play Duration reported on the main menu pause while a manual or automatic save is being completed.
The game's internal 24-clock runs faster at night to make night duration 10 minutes of real time and the daytime hours 50 minutes of real time.
To do this, the game's clock operates at 10.8x real time during the game's day, and 90x real time during the game's night. 50 actual minutes * 10.8x + 10 actual minutes * 90x = 1440 minutes, the number of minutes in a 24-hour game day. 
The clock runs at 10.8x beginning at game time 07:30 and speeds up to 90x at a game time of 16:30 (4:30pm), 9 game hours later.