The Problem: your calendars aren’t synching with iCloud
If you put appointments into the Calendar app on your Mac, and they don’t show up on your iPhone, the first thing to figure out is, where is the problem? Is it on the Mac? is it on the iPhone? Or is it on iCloud itself?
Pinpoint the problem
Let’s figure out where the problem is. Use a browser to sign into iCloud.com. Are the appointments you made on the Mac in the Calendar app showing up on iCloud.com? If so, we know the Mac is synching with the iCloud service, and the problem is with your iPhone. If not, the problem is probably with your iPhone.
I say “probably” because there is a chance that the iCloud service is down. It doesn’t happen often but it does happen. Here is a link to Apple’s page showing the status of Apple’s online services. Here’s how the page looked when I took this screenshot:
In the picture above we see that the iCloud Calendar service is working.
For our example, let’s assume that iCloud’s system status is green, which means it’s working, and that the appointments you made in the Calendar app on the Mac are not showing up in iCloud. (If you make an appointment in the calendar on iCloud.com it won’t show up on the Mac either. You can test that if you’d like.) That points to a problem with the Mac, and that’s the problem we’ll address here.
You can double-check: make an appointment on your iPhone and see if it shows up in iCloud.com. Or make one on iCloud.com and see if it shows up on your iPhone.
Try forcing the Calendar app to sync
iCloud calendars are supposed to synch all by themselves (look in the Calendar app’s preferences– it should say “Push” in the Refresh Calendars section under “Accounts”) without you needing to do anything. Still, in a not-synching situation like this one you can force the Calendar app to refresh by choosing “Refresh Calendars” from the View menu (shortcut: ⌘-R).
After choosing Refresh Calendars you should see a little spinning progress indicator as shown below. The spinner should disappear in a few seconds, indicating the Calendar app has been refreshed with information on the server, and vice-versa (it’s a two-way sync).
If the spinner does not go away it means there’s a problem with your Mac’s iCloud settings.
(By the way, the reason I’m writing this article tonight is that last night, the spinner that wouldn’t go away was on my own Mac. So this is first-hand experience talking.)
The Answer: sign into iCloud again
Fortunately, the answer is ridiculously easy. Just go to System Preferences, then iCloud (by clicking the Apple ID icon in macOS Catalina’s System Preferences, or by clicking the iCloud icon in the System Preferences in older macOS versions), and then– if you see a message saying “Enter your password to continue using iCloud”– click the “Enter Password…” button, supply your Apple ID password, and you are done.
You’re looking for something like this:
Believe it or not, that’s it.
If the Mac wants you to sign into iCloud it will probably present the iCloud preference pane as soon as you open System Preferences. If you’ve been ignoring the “Some services will not be available until you sign into iCloud” message now you know what “some services” includes. Sign in!
Note: clicking a button in a window that you created (by opening up System Preferences), followed by you entering your iCloud password is totally safe. This is quite a bit different than entering your iCloud password into a form, in a website that came to you via a link in your email. Be careful out there, scammers are everywhere, and they are trying to find out what your iCloud credentials are by getting you to type them into some fake-o website that the bad guys monitor. If you fall for one of those scams you’ll basically be handing them your iCloud username and password. So don’t do that.
In my case, the spinner in Calendar never stopped. It would have spun forever but I got smart before “forever” and clicked the button to enter my iCloud password. Even if they didn’t ask I would have signed out of iCloud and then signed back in. Fortunately, the message was right in front of me as soon as I went to iCloud, and once I’d entered my iCloud password allowed synching to work once again.
(There are many ways to go wrong with iCloud calendar synching– you might not have an internet connection, the event might be in an “On My Mac” or “On my iPhone” category, you might not have a checkmark next to the calendar the event is in– so it’s possible that the solution presented here might not solve your problem. But then again it might, and it’s super easy to try, so give it a whirl and see what happens. If this does solve your problem let me know in the comments.)