How to fix macOS Calendar app not syncing with iCloud or showing wrong events on your Mac

Summary

This guide helps you troubleshoot and resolve: How to fix macOS Calendar app not syncing with iCloud or showing wrong events on your Mac. Follow the steps below to fix the issue.

Common Causes

The macOS Calendar app is generally reliable, but syncing problems can occur when connecting to iCloud, Google, or Microsoft 365 accounts. Common symptoms include missing events, duplicated appointments, events showing in the wrong timezone, or calendars that refuse to update. Most of these issues can be resolved without losing any data by working through a few systematic checks.

Quick Fix Steps

If you're short on time, try these steps first. They resolve the majority of Calendar syncing issues:

1. Check your internet connection by opening Safari and loading a webpage.
2. Confirm the system date and time are correct under System Settings > General > Date & Time.
3. Toggle Calendars off and back on in System Settings > Internet Accounts for the affected account.
4. Quit and reopen the Calendar app.
5. If the issue persists, restart your Mac.

If events are still missing or showing incorrectly, continue to the detailed instructions below.

Detailed Instructions

Verify Your Internet Connection and System Date

Calendar relies on accurate time settings to sync events correctly. A wrong date, time, or timezone is one of the most common causes of events appearing at the wrong time or not showing at all.

1. Click the Apple menu and select System Settings.
2. Click General in the sidebar, then click Date & Time.
3. Ensure Set time and date automatically is turned on.
4. Click Time Zone and confirm your region and city are correct, or turn on Set time zone automatically using current location.

Check Account Status in Internet Accounts

The Calendar app pulls its data from the accounts configured in Internet Accounts. If an account is disabled or showing an error, its calendars will stop syncing.

1. Open System Settings and click Internet Accounts.
2. Select the affected account (iCloud, Google, or Microsoft 365).
3. Confirm the Calendars toggle is switched on.
4. If you see a yellow warning icon or red status indicator, click it for details. You may need to re-enter your password.

For each account type, also confirm:

• iCloud: You are signed in to iCloud and have an active internet connection. Visit icloud.com in Safari to verify your account is working.
• Google: You are using App Passwords if your Google account has two-factor authentication enabled. Standard account passwords will be rejected.
• Microsoft 365: Your subscription is active and the account is not locked. Check outlook.office.com in Safari to confirm.

Toggle the Calendar Sync Off and On

Forcing a fresh handshake between macOS and the calendar server often clears stuck sync states.

1. Open System Settings > Internet Accounts.
2. Select the affected account.
3. Switch the Calendars toggle off, wait ten seconds, then switch it back on.
4. Open the Calendar app and wait two to three minutes for events to repopulate.

Check Calendar Visibility Settings

Sometimes events appear to be missing simply because the relevant calendar is hidden in the sidebar.

1. Open the Calendar app.
2. Look at the sidebar on the left. If no calendars are visible, click View in the menu bar and choose Show Calendar List.
3. Tick the box next to each calendar you want to display.
4. Right-click (or Control-click) any calendar and choose Get Info to confirm the account it belongs to and check for any error messages.

Review Calendar Preferences

macOS has a few preferences that affect how events are displayed and synced.

1. Open the Calendar app.
2. Click Calendar in the menu bar and select Settings (or Preferences on older macOS versions).
3. Click the General tab.
4. Confirm the Default calendar and Time zone settings match your expectations.
5. Set Show events in to your local timezone if events are appearing at the wrong time.

Remove and Re-add the Account

If the account still will not sync correctly, removing and re-adding it forces a complete rebuild of the sync relationship. Your events remain safely stored on the server.

1. Open System Settings > Internet Accounts.
2. Select the affected account and click Remove Account (or Sign Out for iCloud).
3. Restart your Mac.
4. Return to Internet Accounts and click Add Account.
5. Select the provider, sign in with your credentials, and enable Calendars.
6. Open the Calendar app and allow several minutes for events to download.

For Microsoft 365 and Exchange Accounts

Microsoft accounts use a different sync method and occasionally need additional configuration.

1. Open System Settings > Internet Accounts and select the Microsoft account.
2. Click the Account section to expand it.
3. Confirm the User name matches your full email address.
4. If your organisation uses Exchange, ensure the Server field is set to outlook.office365.com and the Domain field is left blank unless explicitly required.
5. Toggle Calendars off and on again to trigger a resync.

For Google Accounts

Google disabled less secure app access in 2022. If your Google account has two-factor authentication enabled, you must generate an App Password to use with macOS Calendar.

1. Sign in to myaccount.google.com in Safari.
2. Go to Security and confirm 2-Step Verification is active.
3. Under Security, select App passwords.
4. Generate a new app password for Mail or Other (named "Mac Calendar").
5. Use this 16-character password when adding or re-authenticating the Google account in Internet Accounts.

Troubleshooting

Events Show in the Wrong Timezone

This usually means the Calendar app is set to display events in a timezone other than your current one.

1. Open Calendar > Settings > General.
2. Change Time zone to your local region.
3. Restart the Calendar app.

Duplicate Events Appearing

Duplicates typically occur when the same calendar is synced from two sources, or after an account has been removed and re-added without first clearing local cached data.

1. Open the Calendar app and look at the sidebar.
2. Check whether the same calendar appears twice under different accounts. If so, untick the duplicate to hide it.
3. If duplicates appeared after re-adding an account, remove the account again, then in Calendar > Settings > Accounts, remove any orphaned entries.
4. Re-add the account and allow time for a clean resync.

Calendar App Crashes or Freezes on Launch

If the Calendar app will not open or freezes immediately, its preference files may be corrupted.

1. Quit the Calendar app if it is running.
2. Open Finder and select Go > Go to Folder from the menu bar.
3. Type ~/Library/Containers/com.apple.Calendar and press Return.
4. Move the Data folder to your Desktop as a backup.
5. Reopen the Calendar app. A new Data folder will be created automatically and events will resync from the server.

Notifications Not Working for Calendar Events

If you are not receiving alerts for upcoming events, check the notification settings.

1. Open System Settings > Notifications.
2. Scroll down and click Calendar.
3. Ensure Allow notifications is turned on.
4. Confirm the alert style and notification timing match your preferences.
5. Open Calendar > Settings > Alerts and confirm alerts are set to Show notification message.

When to Contact Support

If you have worked through all of the steps above and your Calendar app is still not syncing correctly, the issue may be with the account provider rather than your Mac. In that case:

• For iCloud issues, check Apple's System Status page for any ongoing iCloud outages.
• For Google issues, visit the Google Workspace Status Dashboard.
• For Microsoft 365 issues, check the Microsoft 365 Service Health page.

If all services are operational and the problem persists, contact your IT support team or Apple Support for further assistance.

Still Having Issues?