Turnover, not hours
The right answer is not 'eight hours'. It is however long it takes your pump to move your pool's volume through the filter, then a margin on top of that.
That depends on gallons, pump flow rate, plumbing size, and filter condition. Two houses on the same street with the same pool size can need meaningfully different schedules.
Season by season
Summer heat, sun, and bather load all accelerate chlorine demand and algae growth, so summer needs the longest run time of the year — often split into two blocks rather than one.
Spring and fall can run shorter, but leaf drop pushes it back up temporarily. Winter can run shortest of all, right up until a freeze, when the pump running continuously is what keeps water from sitting still in the pipes.
Variable speed changes the math
A variable speed pump run longer at a lower speed usually filters better and costs less than a short blast at full speed. Slower water spends more time in the filter and skims more gently.
Speed still has to be high enough to run your cleaner, skim the surface properly, and trip any flow switch on a heater or salt cell. Finding that floor is part of a runtime check.
The mistake that costs the most
Cutting run time to save on electricity, then buying extra chlorine and algaecide to compensate. That trade almost never comes out ahead, and it puts the pool one hot week away from turning.
