shared calendar updates not coming through

Question

When my employees make a change to their shared calendar, sometimes the changes they make don't show up when I view the shared calendar.

Answer 1

Hi @Eric Watts [KDA],

Welcome to the Microsoft Q&A forum.

Based on your description, sometimes you may not be able to see the changes in the shared calendar.

Please try the following methods and check whether the issue is resolved:

1/ Remove and re-add the calendar.

2/ Clear the Outlook cache.

For Outlook Web, please press Ctrl + Shift + Delete > Clear now.

If you are using a different version of Outlook, you can refer to the following documentation:

Clear the Office cache - Office Add-ins | Microsoft Learn

At the same time, there is currently an incident reported in the Microsoft 365 Admin Center related to creating Teams Meetings from shared calendars. In some cases, the Teams meeting may not appear or may fail to be created successfully in the shared calendar.

You can refer to more information using incident ID EX1327187 in the Microsoft 365 Admin Center.

 I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this.   

Thank you for your patience and your understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.

I look forward to continuing the conversation.

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Answer 2

Shared calendar changes may not sync reliably if the calendar is still using the legacy sharing model instead of the new Microsoft 365 shared calendar platform.

To improve reliability and ensure updates come through consistently, upgrade the shared calendars and enable the shared calendar improvements:

1. Confirm the calendar owner is hosted in Exchange Online and has explicitly shared the calendar with the viewer.
2. In Outlook (for the person viewing the shared calendar):
   • Go to File > Account Settings > Account Settings.
   • Select the Microsoft Exchange account and choose Change....
   • Select More Settings > Advanced.
   • Check Turn on shared calendar improvements.
   • Close dialogs and restart Outlook.
3. Upgrade existing shared calendars to the new model:
   • In the Calendar module, right-click the shared calendar and select Delete Calendar (this removes only the shared view, not the owner’s data).
   • Close and restart Outlook.
   • From the Calendar Home ribbon, select Add Calendar > Open Shared Calendar... (do not use Add from address list).
   • Enter the calendar owner’s name and select OK.
   • Wait a few minutes for the initial sync; large calendars may take longer.

After this upgrade, shared calendars use the new model that syncs changes more quickly and consistently across devices.

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References:

• How to enable and disable the Outlook calendar sharing updates
• Calendar sharing in Microsoft 365