That's right, @kaktuspalme. Linux by default assumes the real time clock (RTC) is set to UTC, whereas Windows 10 assumes it is set to Local Time. The solution is to force Windows 10 to always assume that—as in Linux—the RTC is set to UTC. Merging the following
.regfile into the Windows registry does just that, and dual boot of Linux/Win10 will then abide happily together keeping the correct time without further intervention.
The registry file:
Create a plain text file with the following content, and save it with the
.reg extension. Then double-click this file in your file manager to merge with the registry. Or edit the registry key manually using
Windows Registry Editor Version 5.00