I am guessing the OP is a new PPL so it is reasonable to assume it would be longer than one for an experienced current pilot.
That been said it should not exceed a hour in the air. After that you are either being milked or there are fundamental skill deficits which are outside the scope of a "checkout" and need to be fixed with a properly briefed instructional flight
Checkouts for experienced pilots seem to come in at two extremes. Either the shortest possible flight to check the box for somebody who is clearly qualified or an absolute horror show as the person demonstrates the toxic effects of years of accumulated bad habits, complacency, and hubris.