My least productive time of the day is 20-30 minutes before a meeting.
I know that the meeting is coming, so I don’t want to be deep in the middle of something when that moment to leave my desk comes. So I end up doing a bunch of small things that are somewhat productive, but not the big kind of productivity I like to have. Meetings should be back to back, so you can free up other time for larger blocks of work.
Although at Intuit, I remember being in back-to-back-to-back meetings and never had time to actually produce anything.
Ooops, time to go to a meeting.