[tz] [tz-announce] 2018f release of tz code and data available

Paul.Koning at dell.com Paul.Koning at dell.com
Mon Oct 22 18:04:13 UTC 2018



> On Oct 22, 2018, at 1:56 PM, Florian Weimer <fweimer at redhat.com> wrote:
> 
> 
> [EXTERNAL EMAIL] 
> Please report any suspicious attachments, links, or requests for sensitive information.
> 
> 
> * Paul Eggert:
> 
>> Stephen Colebourne wrote:
>>> It would be much better for the upstream source to represent the data in a
>>> more standard and backwards compatible way.
>> 
>> The original Japanese regulation does seem to say that the transition
>> occurs Saturday at 25:00 (as this is how such times are often
>> expressed in Japan), and it's better to represent data as close to the
>> original as the format allows. This is not a recent change to the
>> format, which was relaxed to allow 25:00 (and other out-of-range
>> times) in 2007, as first proposed here:
>> 
>> https://mm.icann.org/pipermail/tz/2007-May/014341.html
>> 
>> with no disagreement at the time.
> 
> What's the exact algorithm for normalizing the date?
> Is there only one possible way of doing this?

It seems reasonably obvious and unambiguous, but perhaps it's worth a few lines in the theory file.  Hours are simply offsets from midnight of the stated day, so 25:00 means plus one day plus one hour.  Similarly, days of the month are offsets from the start of the month (one-based), so January 0 is the beginning of the day one day before the start of January.  (That notation appears in the definition of the second, two or three definitions ago.)

	paul




More information about the tz mailing list