In article ,
"Dave Plowman (News)" wrote:

In article ],
isw wrote:
The bottom line is that unless you synchronize it with a "reference"
timekeeper, it *will not* run at the correct rate. The only question is
how fast it will drift. NTP clients (*good* ones) can deal with the
problem amazingly well, but only if the host's network connection is
pretty much continuous and the host essentially does not sleep.

My machine is switched off when not in use. The prog which synchronises
the machine time to the network runs at boot. It also tells you what it's
done. And perhaps a couple of times a week it adjusts the time by a few
seconds. So the internal clock is near as accurate as an ordinary quartz
battery one. I'm not quite sure just when it would matter if the internal
clock was a few seconds out anyway.

That just jams the clock to the correct time once in a while. In between
those times the clock still runs at the same rate it always did, which
is not correct.

What the NTP process does is essentially to monitor the local clock
compared to a reference to understand just what its errors are, and
synthesize a "perfect" clock from it. The synthesized clock can remain
within a few microseconds (or better) of a reference timekeeper all the
time.

Isaac