Only Microsoft could think of treating BIOS time as local time, whilst all the rest operating systems treat it as UTC.
That creates a lot of trouble out of thin air if you dualboot Windows and any other operating system, say Linux. Luckily, certain Windows versions alow to change this. You must add this string to your Windows registry, and the easiest way to do that is importing a reg file.
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlTimeZoneInformation]
“RealTimeIsUniversal”=dword:00000001
Reboot and Windows will start treating local time as UTC.