Re: [time-nuts] MSF maintenance day
I recorded one of the 2009 outages: https://www.youtube.com/watch?v=1vQPgcja770 I probably have some of the raw data somwhere. They actually turned it on and off a few times over the period. David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Leap-second capture on laptop
On Sun, Jan 01, 2017 at 05:05:45AM -0800, Hal Murray wrote: > gha...@gmail.com said: > > No NTP was running. > What software told the kernel that there was going to be a leap second at the > end of the day? I guess it was part of systemd? https://wiki.archlinux.org/index.php/systemd-timesyncd David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] new year crashes
On Sun, Jan 01, 2017 at 12:54:19PM +, Adrian Godwin wrote: > I wonder if someone wasn't ready for their extra second : > http://www.bbc.co.uk/news/uk-38482746 If, as the article says, they had to record things manually from 00:30 to 05:15 GMT, then I guess it probably wan't leap second related? David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Leap second - MSF time signal
On Sun, Jan 01, 2017 at 02:28:23AM +, Deirdre O'Byrne wrote: > https://www.youtube.com/watch?v=FpBxB2Yqh-U Nice. > Starting at 23:58:00 - > A 1000101101001011000111010001110110010110 > B 10001000 > > Starting at 23:59:00 - > A 1101111010110 > B 11100 My decoder seemed to give something like this: A: 000101101001011000111010001110110010110 B: 0001000 Raw: 31/12/2016 23:59 Sat -400 No-DST Ctime: Sat Dec 31 23:59:01 2016 A: 0001011110100010110 B: 11000111000 Raw: 1/1/2017 0:01 Sun 600 No-DST Ctime: Sun Jan 1 00:01:01 2017 Which shows it switching at the right time. There's a long wave spectrum at: http://www.maths.tcd.ie/~dwmalone/time/leap2016/leap2017010100.png or an animated verion at: https://www.youtube.com/watch?v=9Y_DQZN88HQ I think the time codes relate transmitted relates to the minute following the one in which they are transmitted according to: http://www.npl.co.uk/upload/pdf/MSF_Time_Date_Code.pdf Could that explain what you saw? David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Leap second to be introduced at midnight UTC December 31 this year
Hi Hal, I guess you know this but... > I wasn't considering refclocks to be "core" in that context. Got a better > word? > Have you found any similar code that isn't in one of the refclocks? ntp_loopfilter.c used to have code that restricted the months for leap seconds. The new core ntpd code doesn't do this check, though if you have an up-to-date leapseconds file, it will veto bad suggestions. David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Leap second to be introduced at midnight UTC December 31 this year
On Wed, Jul 20, 2016 at 01:05:59AM -0700, Hal Murray wrote: > g...@rellim.com said: > > Yes, I know the problem being solved. Like today, the leap second being > > broadcast sooner than ntpd expects, so it picks the wrong month. > Do you know of any ntp servers that have picked the wrong month? When I was writing up my leap second measurements, I went looking for reports of leap seconds in unusual months (i.e. not in June/Decembet) and managed to find the following: http://lists.ntp.org/pipermail/questions/2007-October/015655.html http://lists.ntp.org/pipermail/questions/2012-August/033611.html http://lists.ntp.org/pipermail/questions/2013-July/035664.html For the first, I think Windows was involved? For the second, I'm not sure how many people accidently leaped. For the last, there was definitely one leap. David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] End Of The World
On Thu, Jul 02, 2015 at 04:47:02PM +, Frister wrote: To be honest, I didn't know that the sleep command could be utilized with a 1 Foolish of me to not have tried it. It's an extension, as sleep used to only work with integer numbers of seconds, e.g. http://pubs.opengroup.org/onlinepubs/9699919799/utilities/sleep.html#tag_20_118 however, it's pretty widely supported these days. David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Time in Phone System
On Mon, Jul 21, 2014 at 11:01:19PM -0700, Hal Murray wrote: I expect that there's date and time information being sent in the header of every phone call, maybe even before the first ring along with the Caller ID info. Wiki says CallerID is sent between the first and second ring, and includes the date and time. http://en.wikipedia.org/wiki/Caller_ID#Operation Some old modems will happily decode it for you. I compared it to NTP at some point last year. The time stamp was only given to the nearest minute, and for my exchange it was pretty terrible - it was slow by about 90s for a few months. I was considering adding it to my leap second measurements, but there didn't seem to be much point. David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] clock and cannon at noon story
I think a version of this story is included in Derek Howse's Greenwich Time and Longitude book, in relation to the shutting down of the telegraph-based time service from Greenwich. See here, on page 115: https://archive.org/details/GreenwichTime He even gives a reference for the story. David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Mains frequency
On Sat, Nov 16, 2013 at 09:26:10AM -0800, Chris Albertson wrote: The signal is 120 volts. You hardly need to amplify it. I tried this a slightly different way. Since there is mains noise everywhere, I made a small loop and connected it to a 3.5mm jack and then plugged that into the mic socket on a sound card. You can get lots of (slightly noisy) samples per second. I took chunks of this data and took the Fourier transform to find the dominant frequency: http://www.maths.tcd.ie/~dwmalone/time/leap2012/#mains but I guess you could filter it and count crossings too? David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Warped back to 1993
On Sun, Aug 11, 2013 at 03:12:00PM +0200, Magnus Danielson wrote:
I'm sure that the NTP drivers can be hacked to make necessary
adjustments without too much code.
I seem to have been caught by the same time warp (or a similar one)
on a GPS unit that I've been using with our NTP server since 1999.
I doubt I will be able to update the firmware, so I've made the
change shown below to the NTP NMEA refclock. It assumes that your
GPS unit might be slow by a multiple of 1024 weeks, and trys to get
the timestamp within 512 weeks of the current system time before
feeding it to NTP.
The patch seems to work for me, though it may not be pedantically
correct. Hal might have some comments on if it could easily be
improved. It might be an interesting option to have in the NMEA
driver, but it does seem a litle hacky.
David.
--- refclock_nmea.c.orig2010-11-10 03:38:22.0 +
+++ refclock_nmea.c 2013-08-13 20:05:44.0 +0100
@@ -979,6 +1076,8 @@
date.yearday = 0; /* make sure it's not used */
DTOLFP(pp-nsec * 1.0e-9, reftime);
reftime.l_ui += caltontp(date);
+ while (reftime.l_i + 512*7*86400 rd_timestamp.l_i)
+ reftime.l_i += 1024*7*86400;
/* $GPZDG postprocessing first... */
if (NMEA_GPZDG == sentence) {
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