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><P
> The Linux software clock is not always accurate. It is
kept running by a periodic <I
CLASS="GLOSSTERM"
>timer interrupt</I
>
generated by PC hardware. If the system has too many processes
running, it may take too long to service the timer interrupt, and
the software clock starts slipping behind. The hardware clock
runs independently and is usually more accurate. If you boot
your computer often (as is the case for most systems that aren't
servers), it will usually keep fairly accurate time. </P
><P
> If you need to adjust the hardware clock, it is usually
simplest to reboot, go into the BIOS setup screen, and do it
from there. This avoids all trouble that changing system time
might cause. If doing it via BIOS is not an option, set the new
time with <B
CLASS="COMMAND"
>date</B
> and <B
CLASS="COMMAND"
>clock</B
>
(in that order), but be prepared to reboot, if some part of the
system starts acting funny. </P
><P
> A networked computer (even if just over the modem) can
check its own clock automatically, by comparing it to some other
computer's time. If the other computer is known to keep very
accurate time, then both computers will keep accurate time.
This can be done by using the <B
CLASS="COMMAND"
>rdate</B
> and
<B
CLASS="COMMAND"
>netdate</B
> commands. Both check the time of a
remote computer (<B
CLASS="COMMAND"
>netdate</B
> can handle several
remote computers), and set the local computer's time to that.
By running one these commands regularly, your computer will keep
as accurate time as the remote computer. </P
><P
> XXX say something intelligent about NTP </P
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