Re: Tell Debian to use local time?

[ken <gebser@mousecar.com>]

On 07/06/2014 06:41 AM Andrew M.A. Cater wrote:
> On Sat, Jul 05, 2014 at 04:10:06PM -0500, Nelson Green wrote:
> > (Added inadvertently omitted subject)
> >
> > On Sat, Jul 5, 2014 at 3:01 PM, Erwan David <erwan@rail.eu.org> wrote:
> >
> > > Le 05/07/2014 21:38, Nelson Green a écrit :
> > > > Good afternoon,
> > > >
> > > > This morning I had the mis-fortune of creating a dual-boot system with
> > > > Debian on
> > > > a machine that already had windows installed on. I installed a second
> > > hard
> > > > drive, installed Debian, and almost everything works. But I apparently
> > > > told the
> > > > installer that the system clock is set to UTC, when it is not (because
> > > > windows
> > > > has no real concept of time).
> > > >
> > > > So when I boot to windows the displayed time is the actual local time,
> > > > but when
> > > > I boot into Debian the displayed time is four hours behind local time.
> > > > If I do a
> > > > date -u the time that is displayed is the correct local time.
> > > >
> > > > I have modified /etc/adjtime and removed the UTC line, but every time
> > > > I boot up
> > > > Debian the line re-appears, and the displayed time is still four hours
> > > > behind.
> > > > So how do I tell the Debian system that the hardware clock is set to
> > > > local time
> > > > in an effort to compensate for the lessor system's inability to
> > > > correctly manage
> > > > time?
> > > >
> > > > Thanks,
> > > > Nelson
> > >
> > > You can tell windows to use UTC internally (while still displaying local
> > > time)
> > > see
> > >
> > > http://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Windows/2000/Q_21805674.html
> > Thanks Erwan, but I am afraid I have to leave the windows installation
> > alone.
> > Fortunately I rarely have to mess with windows, and as a general rule I
> > don't
> > lower my standards to theirs, but in this case I have no choice, at least
> > until
> > we can eliminate windows from the equation completely.

This problem has been around for a long time: Windows insists on setting 
the hardware clock to local time.  A fix I came up with long ago was to 
doctor /etc/init.d/ntpd to (re)set the hwclock to UTC on boot.  This was 
on a redhat or opensuse machine, so on a debian machine you'd want to 
edit /etc/init.d/ntp instead.  There wasn't any need to install any 
additional packages to include this one line in that file.


> dpkg-reconfigure -plow tzdata
>
> as root which will allow you to set the global timezone data for your machine.
>
> That way you don't necessarily have to adjust adjtime and can choose which timezone you're in which will
> also sort out the DST "stuff".
>
> Reset the clock using the date command to set the time.
>
> date --set=070511352013
>
> Then run
>
> hwclock --systohc
>
> to set the time in the hardware clock which should then be correct for Windows and Linux.
>
> Myself, I keep computers set to UTC all year round.
>
> AndyC