Wait, I was wrong. This is a mistake I make every single time. I always assume the MSDS will cover the cure time, look, realize I'm horribly wrong, and then look up the Directions (which is where cure time can be found).
Now, normally these kinds of things can range, so you should always check the actual product used. Personally I'd suggest following the standards for aquarium sealant and wait a week or two for it to fully take. But if it says that objects can be submerged after X number of days, that is close to what you are looking for. But waiting longer doesn't hurt