Q: calendar

Hello blasia_baum,

Thanks for using Apple Support Communities.

From your post I understand you've made changes to your Outlook calendar on a Windows PC, and the changes are not appearing on your iPhone.  To start troubleshooting this issue please check to see if you see the changes on iCloud.com.  If you do not see the changes, then troubleshoot Microsoft Outlook by following these steps:

Microsoft Windows (Microsoft Outlook)

After each step, check to see if the issue still exists. 

Check the system requirements

Make sure that your PC meets the iCloud system requirements.

Check your Internet connection

1. Try to go to www.apple.com. If you can’t connect to the Internet, your iCloud calendars and events won’t update in Outlook. Get help with your Internet connection.
2. Try to open a secure website from your PC to see if you can access ports 80 and 443. If the website doesn't open, you don't have access. Contact your Internet service provider for help. Safari requires access to port 443 to push updates between iCloud and your devices.

Check your settings

Open iCloud for Windows and make sure that you're signed in to the same iCloud account that you're using on your other supported devices.

Refresh Outlook

If you recently made changes in Outlook that aren't updating on your other devices (or the other way around), click the Refresh button in Outlook.

Turn off iCloud Calendar and turn it back on

1. Close Outlook.
2. Open iCloud for Windows.
3. Deselect the Mail, Contacts, Calendars & Tasks checkbox and click Apply.
4. Wait a few seconds. Select Mail, Contacts, Calendars & Tasks, and click Apply.
5. Open Outlook.

Make sure the iCloud Outlook Add-in is active within Outlook

In Outlook 2010 and later:

1. Click the File menu.
2. Click Options in the left panel.
3. Click Add-Ins in the left panel of the Outlook Options window.
4. Look at the list of add-ins in the Active Application Add-Ins section.
5. Select the iCloud Outlook Add-in.

In Outlook 2007:

1. From the Tools menu, select Trust Center.
2. Select Add-ins from the left column.
3. Look at the list of add-ins in the Active Application Add-Ins section.
4. Select the iCloud Outlook Add-in.

Make sure iCloud isn’t your default account in Outlook

• In Outlook 2010 and later, select File > Info > Account Settings > Data Files. If iCloud is listed as the default account in the Comments column, select a different account and click Set as Default.
• In Outlook 2007, select File > Data File Management > Data Files. If iCloud is listed as the default account in the Comments column, select a different account and click Set as Default.

Restart your computer

After you restart your computer, see if you fixed the issue.

Find your calendars in Microsoft Outlook

Learn how to manage Add-ins with Microsoft Outlook.

1. Make sure Calendar is turned on in iCloud for Windows.
2. Look for your data in the iCloud folder within Outlook. You can also view your data in Deleted Items in your Outlook Folder List.

If you find your calendar data in the Deleted Items folder, it isn’t because iCloud removed your data. When you turn on Mail, Contacts, Calendars & Tasks in iCloud for Windows, iCloud copies your calendar data from the default Outlook .pst file to iCloud. Then iCloud removes the calendar data from the .pst file by placing it in the Deleted Items folder in Outlook. The calendar data then moves to the iCloud data set within Outlook, so that iCloud can push the data to and from Outlook.

If you are seeing the changes on iCloud.com, then the issue has been isolated to iCloud on your iPhone.  To troubleshoot iCloud Calendar on the iPhone please follow the steps below.

iOS

After each step, check to see if the issue still exists.

Turn on iCloud Calendar and update your device

• In iOS 7 or later, tap Settings > iCloud on your iPhone, iPad, or iPod touch and make sure that Calendar is turned on.
• Install the latest version of iOS that's supported by your device.

Check your Internet connection

1. Open Safari and go to www.apple.com. If you can't connect to the Internet, your iCloud calendars and events won’t update in the Calendar app. Get help with your Internet connection.
2. Try to open a secure website from your iOS device to see if you can access ports 80 and 443. If the website doesn't open, you don't have access. Contact your Internet service provider for help. Safari requires access to port 443 to push updates between iCloud and your devices.

Refresh your calendars

1. Open Calendar and tap the Calendars tab to load the Calendars list.
2. Pull down on the list to refresh.

If you’re seeing issues with the iCloud Birthdays calendar, remember that it updates hourly. It might take up to an hour for changes to the birthday field in iCloud Contacts to show up in iCloud Calendar.

Check your default Calendar account 

If you store and edit your events using your iCloud account instead of a third-party account, like Google or Yahoo, iCloud will automatically update your calendars.

In iOS 7 or later, see which calendar account your events are updating through:

1. Open the Calendar app on your device and tap an event to view Event Details. 
2. Tap the calendar name to see if the event is updating through an iCloud calendar.

If your device uses multiple accounts like iCloud, Google, and Yahoo, make sure your iCloud calendar is the default Calendar account:

1. On your device, tap Settings > Mail, Contacts, Calendars > Default Calendar. 
2. Tap an iCloud calendar to make it your default Calendar account.

Change your sync settings

1. Tap Settings > Mail, Contacts, Calendars.
2. Under Calendars, tap Sync. If Sync is set to All Events, set it to a specific timeframe, such as Events 1 Month Back. If it's already set to a specific duration, set it to All Events.
3. Tap the Home button. 
4. Wait several minutes. Open Calendar, tap Calendars, and pull down to refresh.

Restart Calendar

Close and restart the Calendar app on your iOS device.

iOS 7 or later:

1. Double-click the Home button to see your open apps.
2. Find the Calendar preview screen and swipe it up to close the app.
3. Press the Home button to return to your Home screen.
4. Wait a minute, then reopen the Calendar app.

Turn off iCloud Calendar and turn it back on

1. Tap Settings > iCloud.
2. Turn off Calendar.
3. You can choose Delete from My [device] if your data exists on icloud.com/calendar and one or more of your devices. Otherwise, choose Keep on My [device].
4. Wait a few minutes, then turn Calendar back on.

Restart your device

Hold down the Sleep/Wake button, then drag the slider when asked to power off. Turn your device back on.

Get help using iCloud Calendar - Apple Support

Take care.