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Re: What time is it, really?

On Thu 09 Aug 2018 at 14:26:30 (-0700), Fred wrote:
> On 08/09/2018 12:42 PM, Brian wrote:
> >On Thu 09 Aug 2018 at 20:39:16 +0200, john doe wrote:
> >
> >>On 8/9/2018 5:00 PM, Greg Wooledge wrote:
> >>>On Thu, Aug 09, 2018 at 10:49:52AM -0400, Jim Popovitch wrote:
> >>>>On Thu, 2018-08-09 at 10:35 -0400, Greg Wooledge wrote:
> >>>>>Whoever suggested that is using outdated information.  Install ntp
> >>>>
> >>>>Why not openntpd?
> >>>>
> >>>>https://packages.debian.org/stretch/openntpd
> >>>Sure, whatever you prefer.  There are at least 4 viable alternatives:
> >>>
> >>>ntp
> >>>chrony
> >>>openntpd
> >>>systemd-timesyncd
> >>>
> >>Systemd-timesyncd is only a client and using sntp.
> >>
> >>https://www.freedesktop.org/software/systemd/man/systemd-timesyncd.service.html
> >Ideal for what the OP wants. Either that or chrony, if he would only
> >make his mind up.
> >
> Well, what makes you think I haven't made my mind up?

(I wasn't the one seeming impatient, but) I was going to enquire at
some time about how you got along with chrony (which you wrote you'd
try next).

The discussion you referred to might have been the one in June last
year when I wrote that chrony did not do a lot for me. I installed
it naively, ie I didn't poke it with chronyc, and the system remained
five seconds slow. OTOH ntp corrected it immediately and stays
precisely correct all the time. (jessie at the time.)
In a follow-up, Brian had more success with chrony.

> Several years ago I built a "network clock" that receives WWVB time
> signals, has a clock display and an Ethernet interface so computers
> on the local network can ask for the time.  The hardware works and
> the software is able to decode the WWVB time code.  I am interested
> in finishing it now.  The computers on the network can use a Perl
> program to get the time.

Interesting. I played around with a Wireless World design in the
early 70's (TTL) where the "Rugby" time code (the slow one) was
decoded in hardware.

Currently we have a consumer radio clock which is a source of mystery
to me twice a year: the DST change occurs in the early evening on
Saturday instead of Sunday morning. In fact, it's about the time
that a UK clock would be changing if they moved on the same weekend
(which they typically don't). What does your home-built clock
reveal about the WWVB codes (assuming our clock is receiving the
same signal in KS)?


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