Date: Sun, 4 Jan 2009 17:05:56 -0800 (PST)
From: david@lang.hm
To: David Newall <davidn@davidnewall.com>
cc: Kyle Moffett <kyle@moffetthome.net>, Ben Goodger <goodgerster@gmail.com>,
       Robert Hancock <hancockr@shaw.ca>, linux-kernel@vger.kernel.org,
       linasvepstas@gmail.com, "Jeffrey J. Kosowsky" <jeff@kosowsky.org>,
       MentalMooMan <slashdot@jameshallam.info>,
       Travis Crump <pretzalz@techhouse.org>, burdell@iruntheinter.net
Subject: Re: Bug: Status/Summary of slashdot leap-second crash on new years
 2008-2009
In-Reply-To: <49614835.7000505@davidnewall.com>
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References: <3ae3aa420901021125n1153053fsdf2378e7d11abbc0@mail.gmail.com>  <20090102210430.49649261@diego-desktop> <495E7849.4030706@shaw.ca>  <495F0672.6020708@davidnewall.com>  <8752a8760901022237r75d408b3i74c703c8ac2d4597@mail.gmail.com> 
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On Mon, 5 Jan 2009, David Newall wrote:

> david@lang.hm wrote:
>> then new zoneinfo files need to be sent out every time there is a leap
>> second (which from other posts on this thread is potentially every month)
>
> Not every few months, for goodness sake!  Leap seconds aren't that
> common!  These files do change regularly, however, sometimes on a yearly
> basis, because that's how often the date might be changed when daylight
> savings transitions.  This is to say that leap seconds don't
> particularly change the frequency of zoneinfo updates.

another poster said that NTP packets include information about this 
month's leap second, so that implies that they could change monthly.

the zoneinfo files normally do not change every year, they only change 
when !$#@$# polititions decide to monkey with things and change the rules 
(for the US this is once in the history of Linus IIRC), the aggregate of 
some country somewhere changing the rules means that more updates are 
created, but most people can ignore those updates if they don't directly 
apply to them.

David Lang
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