What's maximum number of calendars I can publish (can view all details) in outlook?

Hi @Cheng-Yi Lin,

Thank you for reaching out to Microsoft Q&A. 

Regarding your question about publishing multiple calendars with the "Can view all details" permission in Outlook: Microsoft does not officially document a maximum number of calendars that can be published simultaneously with this permission level. However, based on user experiences and community reports (including your own), we’ve observed the following: 

• You can successfully publish up to 19 calendars with full details. 
• When attempting to publish the 20th calendar, the "Publish" button becomes greyed out, indicating a practical or UI-imposed limit. 

This behavior is not currently confirmed in Microsoft’s official documentation, including articles on calendar sharing and view-only calendar publishing. 

If this limitation is impacting your workflow, here are a few suggestions: 

• Consider using shared calendar groups to consolidate visibility. 
• Submit Feedback to Microsoft   
  • Visit: https://feedbackportal.microsoft.com/ 
  • Select Outlook → click “+ Send feedback”. 
  • Describe the issue 
  • Submit your feedback. 
• If you're part of a managed enterprise environment, you may also escalate this through your organization's Microsoft Support channels for further investigation. 

Contact Microsoft Support  

Ticket Support: In the Microsoft 365 Admin Center>Support>Help & Support. You can raise support ticket  

Phone Support: Microsoft provides customer service phone numbers based on your region. You can find the appropriate contact number here.  

If you need any assistance or have further questions, feel free to let me know. 

Warm regards, 

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