Once you’ve determined that draining the pool is absolutely necessary then one more thing to consider is the season. Since we already know that the elements can have an impact on your pool surfaces then it would be safe to say that the best time to drain your pool would be in the fall or in the spring where the weather is considerably milder than in full summer or winter. Avoid times where rain is on the forecast as this can delay your repairs and it can increase the pressure coming from the ground as well.
The downside of draining the pool during the fall is that the temptation to keep the pool empty during winter is high! And the longer the pool sits empty, the greater the risk is of damage to your pool. But if you’re really keen on doing repairs before the winter sets in then just be sure to refill the pool immediately after the repairs are complete, winterise it, and close the pool for the season.
Spring on the other hand is another matter. If you decide to drain the pool and do repairs in spring then once you have done the repairs and refilled the pool, you can actually start your swimming season early with the use or addition of a pool heater! Now that I think about it, this will actually work during the fall as well if you live in an area with relatively mild winters.