Over the past few months, I have experienced my MacBook turning on its fans because of high CPU usage. When that happens, I see that a process called remindd is using 100-300% CPU for a long time, usually more than 10 minutes. It seems this process belongs to the reminders app, which I do use, but it doesn't make any sense that the app has such a high CPU usage. This is not a one time thing, it happened at least 5 times in the last few weeks. I usually ended up killing the process or restarting my Mac. Quitting the reminders app does not stop the process.
What can I do to prevent this?
It may be related to the reminders app constantly syncing:
Although that opens only more questions than it answers.
I'm using the latest MacBook Pro 16" with MacOS 10.15.4 (19E287)
remindd
has run away CPU usage even with syncing off. I updated my answer as well.