Unable to keep HWCLOCK, localtime, UTC along several OSs and partitions.

[Matthew Saltzman]

On Tue, 2012-04-03 at 14:13 -0700, jdow wrote: 
> On 2012/04/03 10:48, luis redondo wrote:
> > I have several operative systems on disk partitions.With the hour change to
> > European Summertime days ago
> > Fedora16 and OpenSUSE are 1 hour less than the right time,the other OSs
> > (Ubuntus,Debian,Solaris etc. are OK).
> >
> > On Fedora16(and OpenSUSE) when I do in Terminal: hwclock ; date ; date --utc I get:
> >
> > 8:53:42 PM WEST
> > 20:53:41 WEST 2012
> > 19:53:41 WEST 2012
> >
> > On Ubuntu(which presents the time OK) I get:
> >
> > sudo hwclock ; date ; date --utc
> > Tue 03 Apr 2012 05:42:26 PM WEST -0.032786 seconds
> > Tue Apr 3 18:42:25 WEST 2012
> > Tue Apr 3 17:42:25 UTC 2012
> >
> > Here the hardware clock equals UTC and on Fedora and OpenSUSE NOT.
> > More,when I fix the time on OpenSUSE and Fedora the other operative systems
> > time become WRONG.
> >
> > How can I fix this?
> 
> 'ix operating systems seem to be sane enough that the hardware clock can be
> set to either UTC or local time. For earlier releases, at least, than today's
> 18, you had a tick mark on the "Time Zone" tab of "Date & Time Properties"
> panel. It hides near the lower left corner.

*nix is generally fine with HWC in UTC or localtime as long as you don't
dual boot.  If you switch OS's in localtime, they may interfere with
each other when it comes to deciding if the HWC is correct local time on
boot and whether to update it on shutdown when daylight changes.  It
also depends on whether all OS's have up to date timezone files.

Once past the changeovers, resetting local time and rebooting should
make everything behave again.  The best strategy is to use UIC for the
hardware clock and make all your OS's conform.  Then whether the
timezone files are right or not, at least no OS should reset the HWC.

> 
> {^_^}
> 

-- 
Matthew Saltzman
Clemson University Mathematical Sciences
mjs AT clemson DOT edu