[tz] [PROPOSED] Use "PST/PDT" for Philippine time
Michael H Deckers
michael.h.deckers at googlemail.com
Fri Jun 22 23:18:28 UTC 2018
On 2018-06-19 19:27, Paul Eggert proposed the changes:
> +# The following alphabetic abbreviations appear in these tables
> +# (corrections are welcome):
> +# 8:00 PST PDT* Philippine Standard Time
> +# *I invented the abbreviation PDT; see "Philippines" below.
> +# From Paul Eggert (2018-06-19):
> +# I surveyed recent news reports, and my impression is that "PST" is
> +# more popular among reliable English-language news sources. This is
> +# not just a measure of Google hit counts: it's also the sizes and
> +# influence of the sources. There is no current abbreviation for DST,
> +# so use "PDT", the usual American style.
> # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
> -Rule Phil 1936 only - Nov 1 0:00 1:00 -
> -Rule Phil 1937 only - Feb 1 0:00 0 -
> -Rule Phil 1954 only - Apr 12 0:00 1:00 -
> -Rule Phil 1954 only - Jul 1 0:00 0 -
> -Rule Phil 1978 only - Mar 22 0:00 1:00 -
> -Rule Phil 1978 only - Sep 21 0:00 0 -
> +Rule Phil 1936 only - Nov 1 0:00 1:00 D
> +Rule Phil 1937 only - Feb 1 0:00 0 S
> +Rule Phil 1954 only - Apr 12 0:00 1:00 D
> +Rule Phil 1954 only - Jul 1 0:00 0 S
> +Rule Phil 1978 only - Mar 22 0:00 1:00 D
> +Rule Phil 1978 only - Sep 21 0:00 0 S
> # Zone NAME GMTOFF RULES FORMAT [UNTIL]
> Zone Asia/Manila -15:56:00 - LMT 1844 Dec 31
> 8:04:00 - LMT 1899 May 11
> - 8:00 Phil +08/+09 1942 May
> - 9:00 - +09 1944 Nov
> - 8:00 Phil +08/+09
> + 8:00 Phil P%sT 1942 May
> + 9:00 - JST 1944 Nov
> + 8:00 Phil P%sT
I am disappointed with these changes. The recent modifications
that removed all "invented abbreviations" have been a step
forward, but the proposed change is a step backward.
Database schemas have to define useful representations of
unknown (or inapplicable) information; SQL has special values
for that purpose. Inventing ad hoc values that cannot be clearly
be identified as such is not a good idea, as is well known.
Following database theory, I consider the numerical
abbreviations, as introduced into tzdb in 2017 to replace
"invented abbreviations", a helpful step in making
the tz database more clearly express what is known
and what is not. These numerical abbreviations clearly
indicate that "there is no known generally used English
alphabetic abbreviation for the time scale
(but the offset from UT is..)".
The 2018e version of tzdb thus seems to represent faithfully
what we really knew at the time about the English acronyms
used for the Manila time scale (except, perhaps, for the
acronym used during the Japanese occupation).
The new information we got about the time scale of Manila
from Republic Act No. 10535 S. No. 3284 H. No. 164, and
from google searches, certainly does not apply to the Manila
time scale in 1899, and it does not even imply that the
common English acronym, if there was one, for the
summer time periods in 1954 and 1978 was different from PST.
But the proposed changes affect all of these aspects.
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.
Zone Asia/Manila -15:56:00 - LMT 1844 Dec 31
8:04:00 - LMT 1899 May 11
8:00 Phil +08/+09 1942 May
9:00 - +09 1944 Nov
- 8:00 Phil +08/+09
+ 8:00 Phil +08/+09 2013 May 30
+ 8:00 PST
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