A quiet evening needs protection from the small obligations that multiply when no plan is named.

An unclaimed evening does not stay empty. Since no plan was announced, it reads as available to everybody, so the errand, the favor, the call and the small job all land in it, and by nine you have had an evening of admin. Rest loses to anything that has a name attached. The protection is not willpower but a stated intention.

Decide what tonight is for and say so, even if the answer is nothing in particular. Treat that as a real commitment when the small requests start arriving.