Dual booting messes with Windows Time

[faginbagin]

On 4/10/2017 11:44 PM, Glenn At Home wrote:
> Hi,
> I noticed my computer clock was hours off, in the future.
> I did some research, and found the following link:
> http://lifehacker.com/5742148/fix-windows-clock-issues-when-dual-booting-with-os-x
> I had just boot up to Ubuntu and rebooted into Windows, and noticed the
> problem.
> So maybe I need to check the time in Linux when I boot up with that drive.
> Where in Ubuntu does one check the clock settings, to automatically
> check time?
> I'm currently in Windows, so I can't check it, but I'm guessing that in
> settings there is something for the clock there.
> This computer is only about a year old, so it would not be the cMos battery.
> Glenn
>
>
>
> Lenny/Glenn/N0YJV
> “Happiness depends more on the inward disposition of mind than on
> outward circumstances.”
> Benjamin Franklin

It's not the time, it's the timezone. It is more likely the problem is 
due to the fact that Windows and Ubuntu make different assumptions about 
what timezone the computer's CMOS clock is set to. Windows assumes it is 
local time. Ubuntu assumes it is UTC. That Lifehacker article describes 
a registry hack to change Windows to assume the CMOS clock is set to 
UTC. I don't recommend that hack, because last I knew it wasn't fully 
supported by Microsoft, even in Windows 10. So what I do is change 
Ubuntu's assumption, using the timedatectl command:

timedatectl set-local-rtc 1

See the following for more info:
https://wiki.archlinux.org/index.php/time

HTH,
Helen