iPhone Calendar Not Syncing? Try These 9 Tips

If you're having trouble with your iPhone calendar not syncing up with your other Apple devices, or vice versa, try these troubleshooting tips to ensure all your calendar events show up correctly on all your devices.

Related: How to Retrieve Deleted Text Messages on iPhone

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iCloud Calendar Not Syncing? Check These Things First

The Calendar app on your iPhone can only sync with other devices through iCloud. Before we get into more involved troubleshooting tips, let's go over a few things that will need to be configured properly for your iPhone calendar to sync with other devices:

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  1. Make sure the iCloud Calendar system is up and running via Apple's site. If the system is down, your iPhone calendar is not syncing, and you'll need to wait until the system is back up and check again.
  2. Go through each of your devices and check that the date and time are correct. If the date and/or time is wrong on one or more devices, that may account for iCloud Calendar not syncing across devices.
  3. If your iCal is not syncing, it may be because you're signed in with different Apple IDs across your devices. Sign in to all of your devices using the same Apple ID.
  4. Make sure you're connected to the internet.
  5. Check your iCloud storage limit: if you have used up all your iCloud storage, your calendar may not sync across devices.

Turn On Calendars in iCloud Settings

For your iPhone Calendar app to sync across all your Apple devices, you'll need to make sure iCloud has access to it. Here's how:

  1. Open Settings.

    Open Settings - iPhone calendar not syncing
  2. Tap on your name.

    Tap name - iPhone calendar not syncing
  3. Tap iCloud.

    Tap iCloud - iPhone calendar not syncing
  4. If Calendars is toggled off, toggle it on.

    Toggle Calendars on - iPhone calendar not syncing
  5. Tap Merge to include all existing local calendars on your iPhone.

    Tap Merge - iPhone calendar not syncing

If Calendars is already on, you can also try toggling it off, then back on again. This may act as a kind of soft "reset." Give it a few minutes, then check to see if your calendars are syncing across devices now.

Enable Calendar Synchronization for All Accounts

If your iPhone calendar is not syncing to your other devices, make sure that your devices are able to send and receive calendar data for all your accounts. Here's how to check this setting on your iPhone:

  1. Open Settings.
  2. Tap Calendar.

    Tap Calendar
  3. Tap Accounts.

    Tap Accounts
  4. Select an account. We've already shown you how to turn on Calendars for your iCloud account above, so here I'll select Gmail.

    Tap Gmail
  5. Toggle Calendars on.

    Toggle Calendars on

Make Sure Calendar Has Access to Mobile Data

If you experience trouble with your iPhone calendar not syncing when not connected to the internet, it may be because your Calendar app does not have access to mobile data. Here's how to make sure your calendars can sync even when you don't have an internet connection:

  1. Open Settings.
  2. Tap Cellular.

    Tap Cellular
  3. Scroll down to Calendar and make sure it is toggled on.

    Toggle Calendar on

Refresh Your Calendar App

Sometimes, if iCal is not syncing, you may just need to refresh the app to give it time to pull up new information. Here's how:

  1. Open the Calendar app.

    Open Calendar app
  2. Tap the Calendars tab at the bottom of the screen.

    Tap Calendars
  3. Swipe down from the top of the screen and wait for the refresh animation to stop playing.

    Swipe down to refresh
  4. Tap Done and see if your calendars have updated.

    Tap Done

Restart the Calendar App

Restarting apps (and devices, but we'll get to that later) is a good catch-all troubleshooting tip when you're having otherwise mysterious trouble. To restart the Calendar app to fix your iPhone calendar not syncing:

  1. Open the Calendar app.
  2. Swipe up from the bottom of the screen to halfway up the screen to open the App Switcher.

    Swipe up to open App Switcher
  3. Swipe the Calendar app all the way up to the top of the screen to close it.

    Swipe up to exit the Calendar app
  4. Tap outside of the App Switcher to return to the Home screen.
  5. Tap the Calendar app to open it again, and see if it has updated.

    Open Calendar app

Disable Low Data Mode

Your iPhone can use Low Data mode to preserve Wi-Fi or cellular data. When it does this, certain functions like app synchronization may be temporarily paused. This may cause your iPhone calendar to not sync. Here's how to turn it off:

  1. Open Settings.
  2. Tap Cellular.

    Tap Cellular
  3. Tap Cellular Data Options.

    Tap Cellular Data Options
  4. Toggle Low Data Mode off.

    Toggle off Low Data Mode

Disable Low Power Mode

Like Low Data Mode with cellular data, Low Power Mode exists to save battery life as much as possible and can also temporarily suspend functions and cause your iPhone calendar not to sync.

  1. Open Settings.
  2. Tap Battery.

    Tap Battery
  3. Toggle Low Power Mode off.

    Toggle off Low Power Mode

Restart Devices

Earlier, we tried closing and opening the Calendar app on your iPhone to fix an iPhone calendar not syncing. If closing and restarting the Calendar app doesn't work, you can also try to restart your devices to get your calendars to sync across all of them. If you're not sure how to restart your iPhone or iPad, you can read this article on restarting your iPhone X or later and how to force restart iPhones and iPads.

Restarting your device may help any malfunctioning apps fix themselves, so after you've booted back up, check your calendar again to see if the syncing issues have resolved themselves.

Remove & Re-Add Calendar

The logic behind this tip is similar to that behind restarting an app or device to fix otherwise mysterious problems. Sometimes, something has gone wrong that you can't easily identify, and the best way to fix it is just to start from scratch. In this final tip, we'll be deleting and then adding a calendar account to help fix issues with iCal not syncing.

  1. Open Settings.
  2. Tap Calendar.

    Tap Calendar
  3. Tap Accounts.

    Tap Accounts
  4. Tap the account you want to disconnect (this will be a third-party account, like a Gmail account).

    Tap Gmail
  5. Tap Delete Account.

    Delete Account
  6. Tap Delete from My iPhone.

    Delete from My iPhone
  7. One your account is deleted, you'll be returned to the Accounts screen. Tap Add Account.

    Add Account
  8. Tap the name of the service you just deleted.

    Select service
  9. Tap Continue.

  10. Sign in to your account using the directions on-screen.
  11. When the account is added back, make sure Calendars is toggled on.

    Toggle Calendars on
  12. Tap Save.


Your account should now be added. Give it a few minutes, then check your Calendar apps across devices to see if that helped. Is your iPhone calendar missing? Here's what to do. Now, learn how to search events in your calendar to make the most of your days!

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Author Details

Elisabeth Garry's picture

Author Details

Elisabeth Garry

Elisabeth Garry is an Associate Editor for iPhone Life. Formerly of Gartner and Software Advice, they have six years of experience writing about technology for everyday users, specializing in iPhones, HomePods, and Apple TV. As a former college writing instructor, they are passionate about effective, accessible communication, which is perhaps why they love helping readers master the strongest communication tools they have available: their iPhones. They have a degree in Russian Literature and Language from Reed College.

When they’re not writing for iPhone Life, they’re reading about maritime disasters, writing fiction, rock climbing, or walking their adorable dog, Moosh.