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Date:      Mon, 26 Jun 2000 17:08:32 -0400
From:      Bob Johnson <bob@eng.ufl.edu>
To:        drew0054@tc.umn.edu
Cc:        questions@freebsd.org
Subject:   RE: adjkerntz & crontab question.
Message-ID:  <3957C650.E6B7ACE@eng.ufl.edu>

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> Date: Mon, 26 Jun 2000 11:45:26 -0500 (CDT)
> From: Zachary Drew <drew0054@tc.umn.edu>
> Subject: RE: adjkerntz & crontab question.
> 
> Thanks but i know what it does, i'm just wondering why its run several
> times in the early morning.

It is checking to see if it is time to adjust your clock for daylight 
savings time.  If your system (hardware) clock is set for UTC (GMT), 
you don't need it and you can disable the crontab entry.

It exists because DOS/Windows actually expect the hardware clock to 
change timezones for daylight savings time, while Unix-derived systems 
expect the clock to always be set to the same time zone (normally UTC), 
and adjust for DST in software.  If your system doesn't need to 
support the DOS/Windows way of doing things (i.e. if you don't boot 
multiple operating systems), you don't need adjkerntz: you should 
just set your hardware clock to UTC, and set the OS timezone info 
so it knows which timezone you want it to display (i.e. your local 
time zone).

-- Bob

> 
> Zach
> 
> 
> On Mon, 26 Jun 2000, Jamie Hermans wrote:
> 
> > Hiya...
> > 
> > Rumour is that it affects daylight savings time.  I think if your time zone
> > does not follow the fall-behind leap-ahead effects, you can remove that
> > line.
> > 
> > As an educated guess: ADJust KERNal TimeZone
> > 
> > Someone correct me if I'm wrong...
> > 
> > ... Jamie
> > 
> > -----Original Message-----
> > From: owner-freebsd-questions@FreeBSD.ORG
> > [mailto:owner-freebsd-questions@FreeBSD.ORG]On Behalf Of Zachary Drew
> > Sent: Monday, June 26, 2000 2:37 am
> > To: freebsd-questions@FreeBSD.ORG
> > Subject: adjkerntz & crontab question.
> > 
> > 
> > 
> > why is "adjkerntz -a" run several times in the early morning from
> > /etc/crontab?
> > 
> > # time zone change adjustment for wall cmos clock,
> > # does nothing, if you have UTC cmos clock.
> > # See adjkerntz(8) for details.
> > 1,31    0-5     *       *       *       root    adjkerntz -a
> > 
> > i've looked in the mail archives and adjkerntz(8) and nothing
> > mentions why it is run several times over a five hour period.
> > 
> > thanks
> > 
> > Zach
> > 
> > 
> > 
> > To Unsubscribe: send mail to majordomo@FreeBSD.org
> > with "unsubscribe freebsd-questions" in the body of the message
> > 
> 
> 
> 
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>


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