Changes to calendar date in BIOS are not reflected in Windows

Applies to: Windows 10, version 1909Windows Server, version 1909 (Datacenter, Standard)Windows 10, version 1903


Consider the following scenario:
  • You have a computer that runs Windows 8 or a later version, or Windows Server 2012 or a later version.
  • In the computer BIOS, you change the calendar date to a value that is earlier than the date that Windows shows.
  • You save the change, and you restart Windows

In this scenario, the Windows date setting does not reflect the change that you made to the calendar date in the BIOS.


This behavior is by design. Windows considers the fact that time does not travel backward. Also, the BIOS on a laptop or notebook device may report a date that is earlier than the Windows date if the battery is failing or dead. In such cases, the BIOS date and time is not reliable.


If you have to change the calendar date on your computer, use the Windows settings to make the change instead of changing the date in the BIOS. This change will be reflected across multiple restarts.

More information

This behavior is new to Windows 8 and Windows Server 2012. Additionally, this behavior does not affect changes to the calendar date in the BIOS if the new date is later than the date that Windows reports.