Windows UTC clock

If you use Windows along with any other OS on the same computer in a dual-boot setup, you will run into the issue that, each time you boot Windows after using another OS, or boot another OS after using Windows, the system clock will show incorrect time until NTP corrects it.

This is because Windows interprets the value stored in the hardware real-time clock as local time, while every other OS interprets it as UTC time. So after boot each OS reads the value and interprets it relative to the wrong timezone, and then after NTP synchronisation it writes time relative to a different timezone than the other OS expects.

To fix the issue, run the following command in Administrator’s Powershell:

Set-ItemProperty -Path HKLM:\SYSTEM\CurrentControlSet\Control\TimeZoneInformation -Name RealTimeIsUniversal -Value 1 -Type DWord -Force

It will change an entry in the Windows Registry, convincing Windows to treat the value stored by the real-time clock as UTC time.