Re: Bug: Status/Summary of slashdot leap-second crash on new years 2008-2009

[Sitsofe Wheeler <sitsofe@yahoo.com>]

david@lang.hm wrote:
> so are you saying that other 'correct' OS's have patches issued every 
> time a leap second is declared so that they have an in-kernel table of 
> them to use to calculate the correct time?

I think the number of other "correct" OSes that actually step the time 
on leap seconds is not that large (at least doing the announcement via 
NTP). According to http://www.ntp.org/ntpfaq/NTP-s-algo-real.htm#AEN2499 
leap seconds are only changed via stepping if you have the right kernel 
discipline (notes on how to check whether a given OS has the kernel 
kernel discipline are mentioned on 
http://www.ntp.org/ntpfaq/NTP-s-algo-kernel.htm#AEN2220 ).

I have a feeling that OSX doesn't do it (there's a mailing list post 
from 2005 where someone was trying to add FreeBSD's ntp_adjtime to 
Darwin 
http://lists.apple.com/archives/Darwin-kernel/2005/Jan/msg00004.html ). 
Additionally folks I know using ntpd synchronized OSX machines said 
their machines were off by one second right after the new year.

Windows is also known not to do it without slewing: 
http://www.meinberg.de/english/info/leap-second.htm#os .