FOLLOW THE BUILDERS RECOMMENDATIONS!!! The pool plaster has to cure with the least amount of variations of the water. Heating the pool prematurely can cause the plaster to delaminate. Swimming too soon can lead to dimples and foot prints in the plaster that will always collect sand and dust and will always look dirty. Not a good idea.
Damage can occur within four hours on a hot sunny. That's only if your pool is plaster. The pool in question is gunite. A gunite pool can stay empty for as long as it takes to do the repairs, no long them a month. But you have to make sure, and this is very important, to open the plugs at the bottom of the pool to releave any water pressure that is under your pool, or your pool can lift out of the ground a couple inches. So remember to relieve the pressure relief valves at the bottome of your gunite pool as soon as possible. Our pool is 20 x 40, freeform, gunite inground pool. It's 3ft to 8 ft deep. As soon as the water is about knee high at the deep end, my husband walks in and removes the plugs at the bottom to release the water that is under the pool. It pours out for a few hours then slows to a trickle. The plugs stay open until we are ready to refill. Make sure, however, you put the plugs back in so they don't leak. He uses white plumbers tape around the threads of the plugs to secure a good tight fitting. Good luck, hope everything goes well.
The gunite pool is basically what most people refer to as the in-ground concrete pool. Because this pool will shape to the contours of your yard, it is a great choice for those who want something more unique than the typical vinyl lined pools. The tile on the gunite pool can be cleaned with household tile cleaner when you are doing your deep cleaning of your pool. This requires that the pool be drained and rinsed thoroughly.