[LEAPSECS] Windows Server 2019

[Martin Burnicki]

Steve Allen wrote:
> On Thu 2018-07-19T04:14:12+0100 Stephen Colebourne hath writ:
>> "In addition, there is no standard method for applying this frequency
>> adjustment, so that different implementations may disagree among
>> themselves in addition to the time error with respect to UTC."
> 
> That quote is not from Microsoft, but rather from the
> ION paper by Matsakis, Levine, and Lombardi
> That can be got by ION members, or from USNO if their
> webserver recovers, or from researchgate if you can
> tolerate the javascript that will try to execute
> https://www.researchgate.net/publication/323600621_Metrological_and_legal_traceability_of_time_signals

Thanks for the pointers.

> Microsoft seems to be documenting a new mode of OS configuration which
> actually does count the second named "60", and specifically in order
> that Microsoft systems can say they conform to MiFID II and other
> regulatory agencies that demand conformance with UTC as defined.
> Otherwise the old default configuration will have a second that lasts
> 2000 millis.

I wonder what you mean by "old configuration". The latest leap second
tests I made with Windows and w32time running showed that there was no
leap second handling at all.

This means whenever w32time polled an NTP server the next time after a
leap second (which could be up to 1 week, with a 1 week polling interval
for machines that are not members oof an Active Directory)) it simply
observed a time offset > 1 s, and adjusted the Windows time accordingly.

Slewing the Windows system time over 2 seconds is a feature of the ntpd
port for Windows (and the Meinberg time adjustment service for their PCI
cards), which implements this slewing as a workaround for windows.

If Windows starts to provide an API to handle leap seconds then these
programs should use the API, if it is available, and skip the workaround.

Martin
-- 
Martin Burnicki

Senior Software Engineer

MEINBERG Funkuhren GmbH & Co. KG
Email: martin.burnicki at meinberg.de
Phone: +49 5281 9309-414
Linkedin: https://www.linkedin.com/in/martinburnicki/

Lange Wand 9, 31812 Bad Pyrmont, Germany
Amtsgericht Hannover 17HRA 100322
Geschäftsführer/Managing Directors: Günter Meinberg, Werner Meinberg,
Andre Hartmann, Heiko Gerstung
Websites: https://www.meinberg.de  https://www.meinbergglobal.com
Training: https://www.meinberg.academy