I don’t think it necessarily indicates ADHD. I mean, obviously it will depend on the person and for some it might. But for me, having something scheduled to do later in the day will mean I can’t fully relax until it’s complete. If I get it out of the way in the morning, then I can relax.
It’s part of the reason when I was in school I could never really relax, even though I wasn’t necessarily doing things all the time. I have a job that I physically can’t take home so I can just chill at the end of the day.