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Anabasis wrote:
> This is really quite simple.  Use the GPS.  GPS birds have atomic
> clocks on them and the only error in the time signal is from the
> transmission delay between the sat and your receiver.
The only necessary word of caution here is that you must make sure that
your GPS receiver is set to display UTC and not GPS time (which is 1980
UT without subsequent leap-seconds and hence is now off by about seven
seconds).   The default, out-of-the-box setting for most GPS receivers
is to show UTC, but it can be changed.
> A website has
> all sorts of network delays as packets get sent to and fro.
These delays can be accounted for by simply measuring the round-trip
delay from the time source to the web browser and back.   www.time.gov
does exactly this, and will even display any remaining uncertainty in
the time display.   For my broadband connection, this number is
typically 0.2 or 0.3 seconds.   I doubt one can set a hack watch this
accurately regardless of the time source.

Lu Abel



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