I have a clear rhythm to my day and I’ll bet you do to.
From 8am to noon on any given day, I can get more done than any 3 afternoons combined.

It’s important to be aware of your natural cycle to maximize productivity.  This is a reason why it’s difficult to schedule a meeting with me in the morning.  By doing morning meetings, which are notoriously unproductive events, I’d be stepping on my best opportunity to get things done.