Typical hours of the day to be out driving on safari?

I am curious as to what times of the day you all typically start out, and come back from safari. I know that if you are on a private safari, you can do whatever you want. But, what time in the morning do you usually (or recommend ) to start out if you want to go out for a fairly early start? 6 AM? 7AM? I’m assuming since you cannot do night game drive in the Serengeti, for example, that you probably have to wait until sunrise to start. True? And also, what time do you ususlly get back to camp if you are staying out for a full day? 5 PM? 6pm? What would you recommend for a end time usually? Thanks!