Re: Why touch the CMOS clock?

Ulrich Windl (
Mon, 13 May 1996 13:31:16 +0200

On 13 May 96 at 1:33, Herbert Rosmanith wrote:

> > # -a Set the system time from the CMOS clock, adjusting
> > # the time to correct for systematic error, and writ-
> ^^^^^^^^^^^^^^^^
> what is a "systematic error" ? the time required to read the CMOS clock
> time ?

Dave Mills calls this "the skew" which is in turn a consequence of
"the drift". The drift is the percentage by which the clock (CMOS)
drifts from a true reference clock. The "skew" then is the current
amount of how far the clock has, well, "drifted". Systematic error
says that this error is reproducible.

So if you know that your CMOS clock is too fast by two seconds each
day, you can correct it that way (clock -a). I hope it's clearer now.

> /herp