With the responding, is that a time thing again?

For example, we really reinforce the rules during the day - in the morning, if I ask him not to do something and tell him if he does it again he will have to sit on the chair, he sits on the chair, by himself, for about 2 minutes.
If it's 5:30 and it's the same scenario, then he sits on the chair but maybe is allowed to take a toy or book, or only sits on it for 1 minute - because while I like to be consistent, when they're tired isn't the time to push the issue or teach something new.

So I guess I'm wondering if he's responding dramatically to any negative consequences moreso as the day wears on? I know both our kids are markedly less resilient as the day wears on. So we just don't choose our battles at the end of the day.