Dual booting causes clocks to go mental!

Yes.

Although only half a year for a user such as myself.

As I’m happily dual-booting between Ubuntu and Windows at the moment, it becomes clear that in British Summer Time (BST), Windows and Linux disagree on how the computer clock should be interpreted.

What’s really a nuisance is that I keep staying up an hour later than I intended!

Basically, the problem boils down to how Windows and Unix-based systems interpret the computer’s internal clock. There’s more about this here, including some pros and cons of either system.

Windows takes the local computer clock time, and treats it as a ‘local’ time. That is, the clock matches the time that it should be in the region. Mac and Linux systems treat the computer’s clock as GMT, and then makes any adjustemnts inside the Operating System.

The bottom line is, unless you’re living in a GMT timezone – you’re going to get the time constantly changing as you switch between operting systems on the same computer.

The simplest way to get around this is to ask Windows to use UTC time instead of local time:

Copy and paste the following into a new file called time.reg

<code>Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation]
"RealTimeIsUniversal"=dword:00000001</code>

Save the file, and double-click on it. Accept the various warnings that appear.

Once Windows has been rebooted, make sure that the clock is set to the correct time. The time should now settle down as you dual-boot between systems.

Now I’ll be able to go to bed at the right time!