[tz] Spain may change time

Brian Inglis Brian.Inglis at SystematicSw.ab.ca
Wed Dec 14 01:01:34 UTC 2016

On 2016-12-13 17:26, Tim Parenti wrote:
> On 2016-12-13 19:12, Paul Eggert wrote:
>> Officially, in the 1918 and 1919 fallback transitions the clock
>> for the long day kept going after 24:00, reaching 24:59 the
>> previous day before falling back an hour to 00:00 the next day.
>> As this behavior is not representable in this database, it is
>> modeled instead as the clock reaching 00:59 the next day before
>> falling back to 00:00.
> Er, remove "the previous day" for consistency about which day we're
> talking about. ;)

...and check the day you end up with is Sunday, unless explicitly 
documented otherwise, and even then, be very sceptical ;^>

We encountered this in an earlier discussion, about war time Italy 
IIRC, where there was ambiguity in a similar "definitive" document 
containing non-explicit tabular data, resolvable by checking the 
weekdays on which time changes fell.

For that and similar reasons, I now detest (standard?) date formats 
that do not include or allow day of week, as a quick reasonableness 
check, as well as UTC offset, for some certainty of the time meant.

Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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