For something like AOW its 30 hours so there is going to be forced rest by your commander. In the past milsims its been stuff like your squad getting assigned to CP security: stationary or patrol. usually during this your squad leader will rotate people for rest, usually 30 mins or so to do whatever you need to: eat, sleep, washroom.
Best way to approach it is with the mindset that you're being deployed far outside the wire. Milsims can be really enjoyable if you prioritize immersion rather than the actual gunfights.