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.

If you're just an ordinary user, it probably doesn't. If you are the
telephone company, or a television broadcaster, though, things really do
work a lot better when the digital signals carried by your network all
are at precisely the same bitrate, no matter where they come from.

A GPS receiver feeding a UNIX box running NTP can give you a local
timebase accurate to about one part in ten (American) billions.

Isaac