The plan you made while rested may need revising by the person living the actual afternoon.

Plans are written by a rested version of you with a clear head and no immediate discomfort. The person who has to carry them out is tired, hungry, and dealing with things the plan knew nothing about. Treating the plan as the authority means the day is being run by somebody who is not actually present for it. A plan is a good guess rather than a contract.

Give whoever is living the afternoon permission to change it, including when that person is you. Decide in advance which parts are genuinely fixed and admit that the rest were only preferences.