Run your pump to:
1) Skim pool surface (big benefit)
2) Filter debris (least concern)
3) Satisfy a salt water generator, chlorinator or heater
There's no hard and fast rules when it comes to pump time. If you can satisfy those three basic criteria in 1 hour, great. If it takes longer, it takes longer.
Many of us use a variable speed pump at low rpms 24/7. My pump uses 200 watts, so it's basically nothing on the electrical bill. Your 1hp 1 speed pump is drinking a lot of electricity, and should be replaced. The VSP replacing it will pay for itself very quickly and also give you a lot more flexibility.