Interim guidance for Cuba’s 2026 daylight saving time change
AI summary
Cuban DST change requires temporary UTC-04:00 workaround
Kubas Sommerzeit-Änderung erfordert temporären UTC-04:00-Workaround
Microsoft announcement
What and why
On October 27, 2026, the government of the Republic of Cuba announced that the country will remain on daylight saving time instead of ending it as scheduled on November 1, 2026. Clocks will not be set back one hour at 2:00 a.m. on November 1. Cuba will remain at UTC-04:00 without interruption until November 7, 2027.
Microsoft plans to release an update to support this time zone change as part of the November 2026 security update. Until then, devices will display an incorrect local time. Affected organizations should use the temporary guidance below until they can install the update.
Rollout schedule
- October 27, 2026: The government of Cuba announced the daylight saving time change.
- November 1, 2026: Cuba’s time change takes effect. Affected Windows devices might display an incorrect local time until the November 2026 security update is installed or the temporary workaround is applied.
- November 2026: A Windows update to support the time zone change is planned for the following supported platforms:
- Windows 11, versions 26H2, 26H1, 25H2, and 24H2
- Windows 10 Enterprise LTSC 2021
- Windows Server 2025, Windows Server 2022, Windows Server 2019, and Windows Server 2016
- November 7, 2027: Cuba is scheduled to end the extended daylight saving time period.
Impact on your organization
Beginning November 1, 2026, affected devices using the (UTC-05:00) Havana time zone will display an incorrect local time until the November 2026 security update is installed, or the temporary workaround is applied.
As a temporary workaround, affected devices can use (UTC-04:00) Georgetown, La Paz, Manaus, San Juan. This option provides the required UTC-4 offset but has different geographic and display information. It should not be treated as a permanent replacement for the Havana time zone.
Action required/recommendations
Beginning November 1, 2026, affected devices in Cuba should use this temporary fixed-offset workaround until the November 2026 security update is installed:
- Go to Settings > Time & language > Date & time, turn off Set time zone automatically, and change the time zone from (UTC-05:00) Havana to (UTC-04:00) Georgetown, La Paz, Manaus, San Juan.
- Install the November 2026 security update when it becomes available.
- After installing the update, turn Set time zone automatically back on. If automatic time-zone selection is enabled and location services are available, Windows will select the appropriate time zone based on the device’s location. Otherwise, manually select (UTC-04:00) Havana.
- Verify that the device displays the correct local date and time. Don’t continue using the fixed-offset alternative as a permanent replacement.
Compliance considerations
No compliance considerations are identified. Review as appropriate for your organization.
Additional information
Change history
- 2026-10-30 · Created · All