The Date, Flotilla, Uboat, and Random folders included in your Commander installation can be used to make Commander enable mods into your game based on the in-game date, the flotilla you're in, the boat you're playing, or at random.
If you make a folder in the Date folder and name it 19410101, for instance, and then put a mod's 'data' folder in it, Commander will write that mod's files into your game when the game is launched but only if the in-game date is on or after Jan 1 1941.
The Random function is a little more complicated to set up, but it can be used to enable different versions of the same mod or file into the game at random every time you launch SH3.
It's referred to, albeit briefly, on page 19 of the Commander user guide.
