Re: [gentoo-user] Re: Winter clock change did not happen

[Mick]

On Sunday 31 October 2010 13:27:11 Nuno J. Silva wrote:
> Mick <michaelkintzios@×××××.com> writes:
> > I dual boot with MSWindows and therefore have set up my /etc/conf.d/clock
> > to:
> >
> > CLOCK="local"
> > TIMEZONE="Europe/London"
> > CLOCK_OPTS=""
> > CLOCK_SYSTOHC="no"
> > SRM="no"
> > ARC="no"
> >
> > I noticed this morning that the clock was still showing summer time (I
> > rarely boot into MSWindows).
>
> Was Linux running since before the time change? I suppose it would at
> least show the right time if that was the case. If it works, you still
> need CLOCK_SYSTOHC="yes" if you want Linux to change the clock.
>
> Linux has no way to know if the time change was done (nor windows),
> unless the systems are syncing with other clock (NTP), so both of them
> will boot up and think this "local" time is the winter time.
>
> The systems may still register if they already did the timezone change,
> so that they know what to do (that was the case with windows 98).
>
> > I had to boot into MSWindows to check what happens there and the clock
> > was showing the new winter time.  After that the Linux clock was also
> > showing the updated winter time.
> >
> > Does this mean that twice a year when the clock changes I need to boot
> > into MSWindows first to allow the time change to take place, or is there
> > a Linux side fix for my dual boot set up?
>
> You can write something so that Linux changes the clock, but then be
> sure Windows is not set to change it.
> my
> A better (read "more complicated") solution would involve some sync
> mechanism between both operating systems so that one can tell if the
> other already changed the clock.
>
> Unless windows now supports UTC clocks, you have to live either with
> this or with an always on winter clock on windows.

Thanks Nuno, this explains well why my Gentoo did not change the time - I do 
not have NTP set up on it and rely on MSWindows to sync with a time server 
once a month or so that I boot into it for just this reason.  This is a new 
laptop and it seems to keep the time reliably for now.  In the future I may 
well set up NTP if I find that the time in Gentoo is drifting (enough for me 
to notice).
-- 
Regards,
Mick