[ntp:questions] Clock Offset

David Woolley david at ex.djwhome.demon.invalid
Wed Dec 19 21:59:25 UTC 2012


Mischanko, Edward T wrote:
> How can my local clock have a negative offset when none of the
*** selected peers have a negative offset?  Is it possible?

It is not clear what you mean by "local clock" and "offset", here.  For 
the normal NTP meanings of these, the offset of the local clock is zero 
by definition.

Could you provide the ntpq, or other, output on which you are making 
this observation, and indicate which fields you are using.

In the normal ntpd sense, the offset of the local clock is always zero 
and the offsets of other sources should be randomly scattered around 
zero, if the time is properly synchronised (the distribution may not be 
symmetric, but can never be one sided, once the clock is locked.

Offset is measured relative to the estimated time measurement from the 
upstream server.  It is not relative any absolute standard of time, 
except after adding all the intermediate errors.



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