Missing movable holidays (Easter-based holidays) in Outlook calendar for 2027 across multiple Microsoft 365 tenants

Question

We are experiencing a consistent issue across multiple Microsoft 365 tenants and organizations.

In Outlook (desktop) and Outlook on the web, holidays for 2027 are partially missing. Fixed public holidays (such as Christmas and New Year) are displayed correctly. However, all movable holidays based on Easter are missing, including:

• Good Friday
• Easter Sunday
• Easter Monday
• Ascension Day
• Pentecost / Whit Monday

This behavior is consistent across:

• Multiple Microsoft 365 tenants
• Multiple users and organizations
• Outlook desktop and Outlook on the web

We have already verified that:

• Calendar synchronization is working correctly
• Holiday calendars are properly added
• The issue is not tenant-specific or client-specific

From our analysis, this only affects movable (Easter-based) holidays, while fixed holidays remain intact.

We are a business IT provider managing multiple customers, and this issue is reproducible across all environments we manage, which suggests a backend or Microsoft holiday data issue rather than a configuration problem.

Could you please confirm:

1. Whether there is a known issue with missing movable holidays for 2027
2. Whether the Outlook holiday dataset for 2027 is incomplete or not yet fully published
3. If there is a planned update to include these missing holidays

Any clarification would be appreciated, as this impacts multiple business environments we support.We are experiencing a consistent issue across multiple Microsoft 365 tenants and organizations.

In Outlook (desktop) and Outlook on the web, holidays for 2027 are partially missing. Fixed public holidays (such as Christmas and New Year) are displayed correctly. However, all movable holidays based on Easter are missing, including:

• Good Friday
• Easter Sunday
• Easter Monday
• Ascension Day
• Pentecost / Whit Monday

This behavior is consistent across:

• Multiple Microsoft 365 tenants
• Multiple users and organizations
• Outlook desktop and Outlook on the web

We have already verified that:

• Calendar synchronization is working correctly
• Holiday calendars are properly added
• The issue is not tenant-specific or client-specific

From our analysis, this only affects movable (Easter-based) holidays, while fixed holidays remain intact.

We are a business IT provider managing multiple customers, and this issue is reproducible across all environments we manage, which suggests a backend or Microsoft holiday data issue rather than a configuration problem.

Could you please confirm:

1. Whether there is a known issue with missing movable holidays for 2027
2. Whether the Outlook holiday dataset for 2027 is incomplete or not yet fully published
3. If there is a planned update to include these missing holidays

Any clarification would be appreciated, as this impacts multiple business environments we support.

Answer 1

Outlook Holiday Calendars - Missing Movable/Floating Holidays

You can Vote for and Comment on this existing Feature Request:

Flexible holidays are missing in the built-in holiday database for 2027 and beyond
https://feedbackportal.microsoft.com/feedback/idea/1eb5ff20-5374-f111-9b47-6045bdbd0989
(You must "Sign In" at the top right of the Feedback page before you can vote).

Answer 2

I would like to first clarify that this is a user-to-user support forum, and we are not Microsoft support. Moderators here do not have backend access and cannot directly intervene in Microsoft products or perform escalations. We can only provide technical guidance and best-practice recommendations based on reported issues.

Hi @S

Based on the information you provided, I understand that you are managing multiple Microsoft 365 tenants as a business IT provider and have identified a consistent, reproducible issue where movable holidays for the year 2027 (such as Good Friday, Easter Sunday/Monday, Ascension Day, and Pentecost) are completely missing across both Outlook desktop and Outlook on the web. Meanwhile, fixed public holidays like Christmas and New Year are rendering perfectly fine, leading you to conclude that this is a broad backend dataset issue rather than a localized configuration error.

After testing this on my end and conducting thorough research, I am seeing the exact same behavior, the 2027 movable holiday data is indeed not updating or appearing on the calendars at this time.

At the moment, Microsoft has not published any official documentation, service health advisories, or release schedules detailing when the complete 2027 holiday dataset, specifically the complex calculation tables required for Easter-based movable holidays, will be fully injected into the cloud backend for Outlook.

Please raise this behavior directly on the Microsoft Feedback Portal. This platform is actively monitored by Microsoft program managers and engineers who prioritize data and feature updates based on corporate demand.

Thank you for your diligence in spotting and tracking this broad issue. Your contribution is incredibly valuable for the community as approach the upcoming calendar years!

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