Up until a week ago I still had all my leftover calendars from my past job. I had unique calendars for: meetings, misc, personal, open work time, and travel. Having a different color for each time of calendar event was helpful for me to quickly scan my day or week to see what I would generally be spending my time doing that week: traveling, going to meetings, open times for working on projects, etc.
But I have no need for multiple calendars now, and so last week I consolidated them all into one. I was shocked to find out that deleting a calendar would mean all of its associated events would be deleted with it, rather than having the option to re-assign them to another calendar. You’ll cringe when you hear what I did: I spent about an hour going through all my repeating and non-repeating events for the next 12 months and assigning them to my personal calendar I was consolidating to.
If I’d had even thought about this painfully-obvious-in-hindsight suggestion form Devir Kahan I could have saved myself a lot of time, and I wouldn’t have lost all of my past events that were on those calendars that got deleted. Live and learn I guess.