The administration of a hybrid deployment that connects on-premises Exchange Server with Exchange Online, enabling seamless integration and centralized control.
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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