Is there a way to remove unneeded time zones from my calendar app?

I often need to switch time zone views in my calendar when setting meetings with folks in other areas or countries, so I keep a few in the list for easy access. EST/PST/etc.)

Unfortunately, I added an event that has a time zone I don't need, and now I can't get rid of it. I've tried EVERYTHING, even suggestions of removing calendar .plist files, terminal, resetting other preferences, and nothing seems to work.

In older versions of Calendar, there was just an option to add or remove time zones in the dropdown at the top as needed, but for some reason they've removed this useful feature at a time when more people are working remotely.

Is there a way to manually control these time zones that appear at the top? It's driving me crazy to have to see all the time zones that were added accidentally when I just want to quickly select one of a couple that I use all the time.