Accurate time without a network connection?

Charles Swiger cswiger at
Tue Apr 22 12:24:59 PDT 2003

On Tuesday, April 22, 2003, at 02:45 PM, David Kelly wrote:
> Looking for options to keep system time moderately accurate at a site
> without network access. So the normal application of ntpd over IP is
> not viable. Dialup modem not allowed either.
> Definition of "moderately accurate": doesn't have to be any better than
> I can set my watch, travel to the site, and set the system time. It 
> just
> has to eliminate "travel to the site."

Ok.  If you run NTPD with only the local hardware clock for a 
reference, wait for a week, and then see how the intrinsic drift of the 
hardware compares with "real time" (using your watch or some other time 
source), you can adjust /etc/ntp.drift by hand.  This isn't going to be 
perfect, but it's going to be much more accurate than doing nothing.


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