[tz] Irish Standard Time vs Irish Summer Time
philip at trouble.is
Fri Jan 19 05:44:15 UTC 2018
On 2018-01-18 19:39:50 (-0500), Tom Lane wrote:
>Zefram <zefram at fysh.org> writes:
>>There was indeed a significant chance of the negative SAVE value
>>breaking alternate zic implementations, and now that that's turned out
>>to be the case that's good cause to postpone this correction, or at
>>least the expressing of it in this natural manner. The tzdb does have
>>unusually high stability requirements. But that's not a reason to
>>keep the database forever inaccurate.
>I'm not sure that it's "inaccurate". The question is more about what
>is the meaning of tm_isdst = 1. It's clear from this discussion that
>an awful lot of code believes it means "local time is advanced now
>compared to what it is when tm_isdst = 0". Arguing that it should
>reflect a legalistic definition of DST, rather than an operational
>definition, is just an argument; it's not conclusive.
>FWIW, I share the opinion that this change was misguided.
I'd go with "premature" rather than "misguided".
Given the number of things this break, I would suggest backing the
change out for now but pointing out in NEWS that it will come back say
one year from now.
Replace the actual change by a comment that the current data is
inaccurate pending software being fixed.
Senior Reality Engineer
Ministry of Information
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