Recently, in order to play World of Warcraft Classic, I dug out an SSD portable drive, installed Windows to Go on it, and set up all sorts of software for gaming. Then I noticed the problem: The time shown under Linux and under Windows is always different Truth is, the reason is simple enough. The two systems handle time differently: Linux sets the BIOS clock to GMT 0 (UTC) and works out the local time from the time zone, while Windows just writes local time straight into the BIOS.