[tz] [PROPOSED] Use "PST/PDT" for Philippine time

Brian Inglis Brian.Inglis at SystematicSw.ab.ca
Sat Jun 23 03:28:48 UTC 2018

On 2018-06-22 17:29, Paul Eggert wrote:
> On 06/22/2018 04:18 PM, Michael H Deckers via tz wrote:
>> I propose to record only what we really have learned since 2018e: the
>> abbreviation PST for Manila time was legally acknowledged in 2013, and it
>> was used later on by some newspapers.

> Generally speaking, tzdb uses current abbreviations even for older timestamps.
> That is, tzdb is designed primarily for today's uses, such as a historian
> writing today about events long ago; it does not attempt to record the long-ago
> abbreviations, such as the abbreviation Filipinos back in (say) 1950 used to
> describe time back in 1950. In that sense, it is like modern historians who
> systematically use the Gregorian calendar even when writing about events that
> took place in Russia in 1914.

> Partly this is to simplify maintenance. That is, it's not merely that tzdb is
> designed for today's uses; it's also that it's easier to keep track of today's
> abbreviations than to also keep track of historical abbreviations used in the
> past. This point is covered in <https://data.iana.org/time-zones/theory.html>,
> which gives the following guideline for abbreviations:

> Use current abbreviations for older timestamps to avoid confusion. For example,
> in 1910 a common English abbreviation for time in central Europe was 'MEZ'
> (short for both "Middle European Zone" and for "Mitteleuropäische Zeit" in
> German). Nowadays 'CET' ("Central European Time") is more common in English, and
> the database uses 'CET' even for circa-1910 timestamps as this is less confusing
> for modern users and avoids the need for determining when 'CET' supplanted 'MEZ'
> in common usage.

TL;DR: it's hard enough finding reliable, accurate sources for time zone and
STD/DST transition data, without adding the burden of also finding reliable,
accurate sources for common English abbreviations used from 1970 or earlier ;^>

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

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