Outlook: Public holiday calendars miss dates after June 2026 and for 2027
Summary
Microsoft confirms that Outlook public holiday calendars may lack holiday entries for the second half of 2026 and for 2027. This affects Outlook on the web, new Outlook for Windows, classic Outlook for Windows and other clients using Microsoft's holiday data. Microsoft is investigating reports from several regions; an alternative holiday source is suggested as a workaround.
Symptoms
- Public holiday calendars stop showing holidays after a specific date in 2026.
- Calendars contain holidays through 2026 but none for 2027.
- Individual holidays are missing or have wrong dates.
- Examples: German Easter-related holidays missing in 2027, Israeli calendars ending in May 2026, Japanese holidays missing for the rest of 2026 and 2027, wrong Singapore Hari Raya Puasa date in 2026.
Affected
- Outlook for Microsoft 365: Outlook on the web, new Outlook for Windows, classic Outlook for Windows and other clients using Microsoft's holiday calendar data
- Reported regions: Austria, China, Denmark, Germany, Hong Kong SAR, India, Israel, Japan, Malaysia, Poland, Singapore, Slovakia, Sweden, United Kingdom, United States
- Additional regions may also be affected
Workaround
- If holiday data beyond what Outlook offers is required, use an alternative source: an organization-maintained holiday calendar, a third-party holiday calendar subscription (ICS) or an official government or regional holiday calendar.
- Note that these are not Microsoft-managed calendars and need separate administration and validation.
- Manually deleting and re-importing calendar data can work for individual users but is often impractical for larger organizations.
Fix
Not fixed yet. Microsoft is investigating.
Recommendation
Check the holiday calendars your staff use for 2027 and the rest of 2026. If planning depends on them, provide a company-maintained or verified ICS calendar centrally and check the Microsoft known-issue page for updates.
Sources
- Classic Outlook: Public Holiday Calendars Missing Dates After June 2026 in Outlook Vendor · support.microsoft.com
Compiled from the sources listed and translated with AI (Claude); status and dates come from the vendor. The vendor’s statements are authoritative. Updated 1 Nov 2026, 18:36.
Where the information comes from
We continuously read the vendors’ official sources, community reports and trade media and summarise them in our own words, with a link to the source:
- Microsoft: Windows release health (Windows 10/11, Server 2016 to 2025), Windows message center, known issues of Microsoft 365 Apps (Outlook, Excel, Word, PowerPoint), Edge, Intune, Autopilot, Windows 365 and Entra Connect, Microsoft KB articles with timelines, Exchange and Windows IT Pro blogs, optionally Microsoft 365 service health and message center
- other vendors: Veeam KB, Citrix (known issues), Ubuntu and Debian (regressions), Broadcom (VMware), Fortinet, Cisco, Mozilla, Let’s Encrypt
- community (title, short excerpt and link only, without the names of the authors): Microsoft Q&A, Microsoft Tech Community (discussions), Veeam R&D Forums, Eleven Forum
- targeted web research with AI (Claude), e.g. on the updates of the month – this also finds discussions on Reddit and in forums; such entries are labelled as community reports until the vendor confirms them
- early warning from trade media (title and link only): Born’s Tech and Windows World, BleepingComputer, AskWoody, Windows Latest, Windows Central, gHacks, The Windows Club, Deskmodder, Dr. Windows, WindowsArea, Frankys Web, heise online
Summary and translation with AI (Claude by Anthropic) – without any data of visitors.
Affected? We can help.
We check whether your systems are affected, apply workarounds properly and plan for dated changes in good time.