[LEAPSECS] negative leap second in 2029?

"Even a few years ago, the expectation was that leap seconds would always be positive, and happen more and more often," Duncan Agnew, a geophysicist at Scripps Institution of Oceanography at University of California's San Diego campus, said in a statement. "But if you look at changes in the Ear

Re: [LEAPSECS] future access to solar time?

The Astronomical Almanac (2019) says ∆UT = UT1 - UTC DUT1 = predicted value of ∆UT, rounded to 0.1 s, given in some radio time signals (Unfortunately, this scan cuts off part of the leftmost characters. But you can deduce them, except perhaps Ee and Eo: equation of the equinoxes and equatio

[LEAPSECS] aircraft GPS receivers hit by leap second bug

[from Flying magazine] Collins Aerospace notified its user base of a cascade of reports it had received beginning at 00:00Z on June 9 that certain GPS and GLU models were not operating properly. The specific models, the GPS-4000S sensor and the GLU-2100 multi-mode receiver (supporting ADS-B Ou

Re: [LEAPSECS] leapseconds, converting between GPS time (week, second) and UTC

On 2019-01-16 1:35, Steve Allen wrote: So starting 1970-01-01 DCF77 changed to broadcast Stepped Atomic Time (SAT) with second markers that were 1 SI second apart except on occasions when they were 1.2 SI seconds apart in order that the time markers would stay close to UT2. For fun (?) I wrote

Re: [LEAPSECS] leapseconds, converting between GPS time (week, second) and UTC

On 2019-01-16 1:35, Steve Allen wrote: Does it know that rubber seconds do not apply to timestamps in central Europe made using DCF77 from 1970-01-01 to 1972-01-01? All my DLL knows is what's in the UTC file. If the file indicates no rate offset in the years 1970-71 and some fractional second

Re: [LEAPSECS] leapseconds, converting between GPS time (week, second) and UTC

On 2019-01-15 10:50, Tom Van Baak wrote: For instance, in Python, if I do a datetime(2016,12,31,0,0,0) + timedelta(hours=30) does it come out as 1/1/2017 6:00:00 or 5:59:59 (it comes out 0600) Here's a C# code fragment which performs a similar computation. To make the demonstration more inter

Re: [LEAPSECS] new delta-T data point

On 2017-10-30 16:23, Tom Van Baak wrote: https://academic.oup.com/astrogeo/article/58/5/5.39/4159289/Solar-eclipse-of-1207-BC-helps-to-date ( https://academic.oup.com/astrogeo/article-pdf/58/5/5.39/20098470/atx178.pdf ) "To facilitate the calculations we adopted the latest solution for the his

Re: [LEAPSECS] Leap second to be introduced at midnight UTC December 31 this year

On 2016-07-25 2:37, Tony Finch wrote: As I understand it the problem with |DUT1| > 0.9s is to do with radio signal compatibility, e.g. MSF only allows |DUT1| <= 0.8s +/- 0.05s One bit of radio trivia is the inconsistent DUT1 limits of the US NIST stations. "UT1 information is broadcast on

Re: [LEAPSECS] USNO press release

On 2016-07-08 12:16, I wrote: Is there a mistake in this announcement? http://www.usno.navy.mil/USNO/tours-events/2016_Leap_Second%20Press%20Release%20-%20Final.pdf WASHINGTON, DC -- On December 31, 2016, a “leap second” will be added to the world’s clocks at 23 hours, 59 minutes and 59 secon

[LEAPSECS] USNO press release

Is there a mistake in this announcement? http://www.usno.navy.mil/USNO/tours-events/2016_Leap_Second%20Press%20Release%20-%20Final.pdf WASHINGTON, DC -- On December 31, 2016, a “leap second” will be added to the world’s clocks at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time

Re: [LEAPSECS] Leap Seconds schedule prior to 1972

On 2016-04-22 1:37, John Sauter wrote: My goal in the paper is to extend the modern definition of UTC back in time. Hence, I use the rules of UTC whenever possible. Thus, extraordinary days are the last day of the month, and are limited to 86,399 or 86,401 seconds. Considering that Morrison an

Re: [LEAPSECS] Civil timekeeping before 1 January 1972

On 2015-03-06 18:02, Harlan Stenn wrote: When we get a bit more down the road with NTF's General Timestamp API, I'd appreciate your taking a look at what we're doing and helping out in any way you are up for. One of the issues that will need more attention is pre-1972 stuff. The rubber time er

Re: [LEAPSECS] My FOSDEM slides

On 2015-03-06 11:04, Brooks Harris wrote: The "rubber-band era" is just entirely irrelevant. Its historically interesting, and may be required for some special application concerning that period, but for practical "UTC-like" timekeeping its just an historical curiosity. This fact is somewhat mor

Re: [LEAPSECS] My FOSDEM slides

I recommend Leap Second Handling (1), "Enumeration of UTC seconds when inserting a leap second" be modified to half second steps: 2015-06-30 23:59:59.0 2015-06-30 23:59:59.5 2015-06-30 23:59: