Accurate time without a network connection?

David Kelly dkelly at
Tue Apr 22 12:44:16 PDT 2003

On Tue, Apr 22, 2003 at 03:26:19PM -0400, Charles Swiger wrote:
> 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.

Good. But already tried that. The situation is multiple systems have to
run with something near the same time, but no bidirectional contact. And
need to operate for years. Letting ntpd tune itself and then free run
works much better than the system clock alone but only good for weeks,
not months.

As for exactly what time the systems have, it doesn't much matter as
long as they all have the same time.

David Kelly N4HHE, dkelly at
The human mind ordinarily operates at only ten percent of its
capacity -- the rest is overhead for the operating system.

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