This is a really neat idea. I usually apply categories to my calendar invites so I can see quickly if I’m spending too much time (or not enough time) toward any type of activity. But I really like your concept since it’s qualitative and truly measurable.

I’m a corporate user and unfortunately locked into Outlook and usually can’t run outside service against my calendar, e.g. calendly. I can occasionally get an Outlook plugin to work though. Have you considered anything like that?