You add an event on your iPhone, glance at your Mac, and it's not there. Or you edit a meeting on the Mac and your phone never gets the memo. When iCloud Calendar stops syncing, the two devices quietly drift apart — and you find out at the worst possible moment, standing in front of a client or missing a call.
The good news: this is almost always a settings or account hiccup, not a broken Mac. Work through the fixes below in order. The first three take under two minutes and solve the large majority of cases.
The 30-second fixes (try these first)
Before anything drastic, rule out the simple stuff. These clear up most sync failures on their own:
- Force a refresh in Calendar. Open the Calendar app and press Command + R (or choose View → Refresh Calendars). This pulls the latest events from iCloud right now instead of waiting for the automatic sync.
- Check you're online. Calendar syncs over the internet. A dropped Wi-Fi connection or a captive-portal hotel network silently stalls it. Load any web page to confirm you actually have a connection.
- Confirm the same Apple Account on both devices. On the Mac: System Settings → [your name] at the top. On the iPhone: Settings → [your name]. If the email addresses don't match, the two devices are syncing to different iClouds — that alone explains a "missing events" problem.
Still out of sync? Keep going.
Step 1: Make sure Calendar is actually turned on for iCloud
This is the toggle most people never check. iCloud can be signed in while Calendars specifically is switched off.
- Open System Settings and click your name at the top.
- Click iCloud.
- Under Apps Using iCloud, find Calendars and make sure it's On.
If it was already on, toggle it off, wait ten seconds, then back on. That single off/on cycle forces a fresh handshake with iCloud and fixes a surprising number of "it just stopped" cases. Do the same on your iPhone under Settings → [your name] → iCloud → See All → Calendars.
Step 2: Check that your events are in the iCloud calendar (not "On My Mac")
Calendar can store events in two very different places, and only one of them syncs:
- iCloud calendars — sync to every device signed into your Apple Account.
- On My Mac calendars — a local-only calendar that never leaves the machine.
Open Calendar and look at the left sidebar (press Command + 1 if it's hidden). If your events sit under an On My Mac heading, that's why the iPhone never sees them. Drag those events onto an iCloud calendar, or when creating a new event, click the calendar name and pick one listed under iCloud.
Step 3: Set the refresh to "Push" or a short interval
Calendar has a hidden setting that controls how often it checks for changes. If it's set to "Manually," nothing syncs until you force it.
- In the Calendar app, open Calendar → Settings from the menu bar.
- Click the Accounts tab and select your iCloud account.
- Set Refresh Calendars to Push (or "Every minute" if Push isn't offered).
Push means new events arrive the instant they're created on another device — the behavior you actually want.
Step 4: Restart, sign out of iCloud, and back in
If the toggles didn't do it, a full account refresh clears out a stuck sync token:
- Restart the Mac. Not sleep — a real Apple menu → Restart. This alone fixes many cases.
- Still stuck? Go to System Settings → [your name] → iCloud → Calendars and turn it off. When it asks, choose to keep a copy on the Mac so nothing is lost.
- Wait about a minute, then turn Calendars back on. The Mac re-downloads a clean copy of your iCloud calendar.
Give it a few minutes after re-enabling — a large calendar can take a little while to rebuild.
Step 5: Check iCloud's system status and your storage
Two outside factors can stall sync even when your settings are perfect:
- An Apple outage. Rare, but it happens. Search "Apple System Status" and confirm iCloud Calendar shows a green dot.
- Full iCloud storage. If your iCloud is completely full, new calendar changes have nowhere to sync. Check under System Settings → [your name] → iCloud — if the bar is maxed out, clearing space (or freeing it up the way we describe in our guide to iCloud Drive and storage) gets sync moving again.
Step 6: The "wrong date is showing" gotcha — time zone support
If your events sync but appear at the wrong time or on the wrong day, sync isn't broken — Time Zone Support is the culprit. In Calendar → Settings → Advanced, try toggling Turn on time zone support. When it's on, events stay pinned to the time zone you created them in; when off, they shift to your current location. Pick whichever matches how you work, and set the same choice on your iPhone.
If it's still not syncing: rebuild the account
A stubborn account that survives every step above usually has a corrupted local cache. The clean fix is to remove and re-add the iCloud account itself:
- Confirm your events are safe in iCloud first — sign in at iCloud.com from any browser and check the Calendar there. If they're on the web, they're safe on Apple's servers.
- On the Mac, go to System Settings → [your name], scroll to the bottom, and Sign Out of iCloud (choose to keep a copy of your data).
- Restart, then Sign back in. Re-enable Calendars.
This forces the Mac to rebuild its calendar database from Apple's clean server copy — the reset that finally clears the most persistent cases.
When it's not the calendar — it's the Mac
If you're on an older macOS version, sync services can misbehave in ways no toggle fixes. It's worth confirming you're current — see how to update macOS. And if the same Mac is also dropping other iCloud services (Messages won't come through, iCloud Drive stalls), the pattern points at the account or the machine rather than Calendar specifically — our guides on iMessage not working on a Mac and recovering files on a Mac cover the neighboring symptoms.
Frequently asked questions
Why is my Mac calendar not syncing with my iPhone?
The two most common causes are (1) the devices are signed into different Apple Accounts, or (2) your events live in an "On My Mac" local calendar instead of an iCloud one. Confirm the same account on both devices, then check that Calendars is toggled on for iCloud on each.
How do I force my Mac calendar to sync now?
Open the Calendar app and press Command + R, or choose View → Refresh Calendars. That pulls the latest events from iCloud immediately instead of waiting for the next automatic check.
Why do events show on iCloud.com but not on my Mac?
That means iCloud has your events but the Mac's local copy is stuck. Toggle Calendars off and back on in iCloud settings, or sign out and back into iCloud, to rebuild the Mac's copy from the server.
Will turning off iCloud Calendars delete my events?
No — when you turn it off, macOS asks whether to keep a copy on the Mac. Choose Keep. Your events also remain safe on Apple's servers and at iCloud.com regardless.
Still fighting a Mac that won't cooperate — slow, glitchy, or stuck on an old macOS it can't update? Sometimes the machine, not the settings, is the problem. Browse all our Mac guides for the next thing to try.