OneCal

Do you have more than one calendar? Maybe a work calendar and a personal calendar? I run at least five because every client creates their own email address and calendar. Now, trying to ensure I go to every meeting, do not accept meetings when I am already busy, and keep everything in sync was a lot of work.

I have looked for various solutions over the years, and nothing has worked the way I want, until recently I found OneCal! It is a solution which can sync multiple calendars (Microsoft and Google) with a variety of rules, like my personal one syncs in but only one way (so work does not fill it up). You can control what data appears in other calendars too.

And they have a great web UI which I use to review my calendar all day. It is fantastic and considering the cost vs. how much I would lose doing this manually... it is practically a no-brainer for how much I save.