Satisfactory allows you to change what time your server restarts with the Server Restart Interval. The time that you see in game is in UTC (Universal Coordinated Time), so make sure that you set this to match a time in your local timezone that you want the server to restart at. At this time, there isn't a way to completely disable the automatic restart, but you can adjust when it happens.
1. Open the Server Settings tab.
2. Drag the slider to a time of your choice.
3. When finished, click Apply. Your server will now restart at the time you chose.