how to get holiday calendar updated

If the issue is the current known problem where Outlook public holiday calendars are missing dates after June 2026 or for 2027, there is no direct fix available yet. Microsoft is actively investigating it.

What can be done now:

1. If holidays are simply missing in Outlook’s public holiday calendar, use a workaround instead of waiting for the built-in calendar to update:
   • Use an organization-maintained holiday calendar
   • Subscribe to a third-party ICS holiday calendar
   • Use an official government or regional holiday calendar
2. In Outlook on the web, an ICS subscription can be added from:
   • Calendar > Add calendar
   • Import or subscribe to an online calendar that supports .ics
   • Subscribed calendars receive automatic updates from that source
3. If using new Outlook or Outlook on the web with a Microsoft 365 work or school account, holiday calendars added there are subscription-based and receive automatic updates when holidays are added or changed:
   • In Outlook on the web: Calendar > Add calendar > Holidays > select the country or region
4. For individual users, deleting and re-adding holiday data can sometimes help, but it is not considered a practical solution for larger environments.

For classic Outlook for Windows, if a specific country’s holiday entries were corrected and a fix is available, the supported pattern is:

• Delete the existing holiday items from the calendar
• Add the holidays again

Example deletion steps in classic Outlook:

1. Go to Calendar.
2. Select View > Change View > List.
3. In Arrangement, select Categories.
4. Find the Holidays category.
5. Select the holiday items for the affected country and delete them.
6. Return with View > Change View > Calendar.
7. Add the holidays again using Outlook’s holiday add feature.

If the problem matches the 2026/2027 known issue, re-importing may help only for some individual cases, but the documented workaround is to use an alternative holiday source until Microsoft resolves the issue.

References:

• Public Holiday Calendars Missing Dates After June 2026 in Outlook | Microsoft Support
• Add a calendar in Outlook on the web | Microsoft Support
• Add holidays to your calendar in Outlook | Microsoft Support
• Holiday is missing and has inaccurate date in Outlook for United Kingdom | Microsoft Support