I bought a couple of 4L water bottles and just follow the expiration date which is about 2 or 3 years. For water meant for cleaning, I fill empty 3.6L bleach bottles of tap water. In theory, if your water containers are sealed and away from light it can withstand easily many variations in temperature and stay drinkable almost indefinitely. But just to be sure, generally it is recommended to rotate stored tap water every six month.

Frankie