At Waterford Hills Club Races we do this:

Sat AM 20 minute qualifying session

Sat PM race (grid position determined by qualifying time)

Sunday AM race (grid position determined by Sat PM finish position)

Sunday PM race (grid position determined by your fastest race lap fom either Sat PM
or Sunday AM race)

The nice thing about his format is that even if you are fast but have a couple of DNF's, for whatever reason, or have an off and lose position, you still have a chance to salvage a decent finishing position in the Sunday PM race.
I suppose that would make the Sat PM and Sunday AM races "qualifying races".