How much notice must a private jet owner give to his pilots before flying?

I flew private jets for 12 years. If you’re waiting at an airport for the owner to finish their business and fly home then it’s pretty quick if they want to leave earlier than planned.

If the jet is in the hanger and hasn’t flown that day then 60–90 minutes if the caterer can get to you that fast, assuming you need catering.

The size of the jet won’t make much difference.