Answers...

to commonly asked questions.

Why aren't my calendars syncing?

I hope this is an easy fix - seems that every since I did all of that upgrading, when I put something on my desktop calendar, it does not go onto my phone. (If I put something on my phone, it does go onto my desktop, however.)

I just went to system preferences - and turned on iCloud Drive, but that didn’t seem to work. Not sure if I should have turned that on….

Seems like something just needs to be turned on, but I am not sure what.
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Calendars can be very confusing. The main reason for this is that almost every email account service we use (gmail, iCloud, aol, exchange, yahoo, etc…) all offer their own calendar and contact syncing to go along with the email. Because of this, sometimes we end up adding events to one calendar but don't have that that calendar on a different device. So the first place to start looking when troubleshooting calendars is to figure out which calendar services you actually need. In a perfect world, one service is the best way to go. For most people this is either iCloud or Gmail's calendar system.

1. On your Mac, open system preferences/internet accounts. Select each account and see if calendars is checked. You will return to this area eventually and uncheck the services you don't want in the end.
2. Open Calendar on your mac and go to preferences, check which is your default calendar. This can be the issue as well. You may be adding an event automatically to the wrong calendar.
3. On your phone, go to the Calendar app, select Calendars at the bottom of the screen and see if you have the same accounts active on your phone as you saw on your computer.
4. Decide if you can eliminate some of these calendars but be aware that if you turn off, say your gmail calendar, then any events on that calendar will go away. So you may have to move those events from one calendar to a different one before you turn that calendar off.

These are good starting points to check. It's rare that calendar and contact issues are technical problems like software issues. It's much more common that we just don't have things set the way we'd like.
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