[LEAPSECS] radio-synched watches

[Zefram]

Tom Van Baak wrote:

>On the other hand, most radio controlled watches (e.g., WWVB

>here in the USA) make a cute jump in time every night, and after

>a leap second, presumably even more so.


In the late 1990s, I was in the habit of wearing a watch, and looked into
getting one of these.  I was shocked to find that they free-ran all day
and then jumped once a day.  As far as I could tell they did not slew to
cope gracefully with the instantaneous time offset, nor did they apply a
correction to the oscillator frequency based on the difference between
multiple time offset measurements.  They didn't handle leap seconds
properly, treating it as just another source of inaccuracy.  Synching
only once a day struck me as poor.  I was also rather put off by them
being only available with analogue displays (and therefore incapable of
displaying a leap second even if they coped with it correctly underneath),
and, ultimately, by them being treated by retail establishments as items
of jewellery rather than as practical machines.

It shouldn't be that difficult to run something like the NTP algorithm
on the watch.  Failing to apply any of the obvious corrections gives the
impression that the manufacturer really doesn't care about telling the
time accurately.  In the absence of any sane product, I gave up on getting
a radio-controlled watch, and eventually gave up wearing a watch entirely.
I now rely on the clock on my mobile phone, which suffers exactly the
same problems as pre-radio watches: it too doesn't do anything like NTP,
despite listening to a radio network *all the time*.  It would be trivial
for the network to slip in a broadcast NTP packet every few minutes,
and then everyone could have mobile access to decent synchronised time.


>http://www.leapsecond.com/pages/Junghans/


That page appears to describe exactly the kind of poor synchronisation
behaviour by which I was so appalled.  The graphs very clearly show the
absence of any slewing or frequency steering.

More than a decade on from the first ones becoming available, are there
now any radio-synched watches that don't suck in such unsubtle ways?

-zefram