"Best" is what works for you, and your pool.
You can find statements on the internet saying anything from "Run it just 4 hours" to "Run it all the time".
In the Southwest, and in Southern Calif -- with DE filters and no thunderstorms and mostly inground pools -- 4 hours is common. In the Northeast , where above ground pools with undersized filters are common, running 24/7 is also common.
What sort of pool, pump and filter do you have? How do you chlorinate? Where are you, and what sort of weather to you have?