From d4c65d53b9ff878291a0b103e0069f24628f6487 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Thu, 5 Sep 2024 13:44:26 -0700 Subject: [PROPOSED] Improve historical data for the Philippines * NEWS: Mention this. * asia (Phil, Asia/Manila): Correct transitions to match Selga 1923 and Philippine proclamations and orders. (Thanks to P Chan.) * zone.tab, zone1970.tab, zonenow.tab: Adjust Asia/Manila coordinates to match longitude given by Selga 1923 and a likely latitude to match, in the harbor. --- NEWS | 16 ++++++++ asia | 113 +++++++++++++++++++++++++++++++++++++-------------- zone.tab | 2 +- zone1970.tab | 2 +- zonenow.tab | 2 +- 5 files changed, 101 insertions(+), 34 deletions(-) diff --git a/NEWS b/NEWS index 83b8b8c8..6ee43e75 100644 --- a/NEWS +++ b/NEWS @@ -1,5 +1,21 @@ News for the tz database +Unreleased, experimental changes + + Briefly: + Improve pre-1991 data for the Philippines. + + Changes to past timestamps + + Correct timestamps for the Philippines before 1900, and from 1937 + through 1990. (Thanks to P Chan for the heads-up and citations.) + This includes adjusting local mean time before 1899; fixing + transitions in September 1899, January 1937, and June 1954; adding + transitions in December 1941, November 1945, March and September + 1977, and May and July 1990; and removing incorrect transitions in + March and September 1978. + + Release 2024b - 2024-09-04 12:27:47 -0700 Briefly: diff --git a/asia b/asia index a2480b02..32c52860 100644 --- a/asia +++ b/asia @@ -3665,21 +3665,70 @@ Zone Asia/Hebron 2:20:23 - LMT 1900 Oct # be immediately followed by 1845-01-01; see R.H. van Gent's # History of the International Date Line # https://webspace.science.uu.nl/~gent0113/idl/idl_philippines.htm -# The rest of the data entries are from Shanks & Pottenger. - -# From Jesper Nørgaard Welen (2006-04-26): -# ... claims that Philippines had DST last time in 1990: -# http://story.philippinetimes.com/p.x/ct/9/id/145be20cc6b121c0/cid/3e5bbccc730d258c/ -# [a story dated 2006-04-25 by Cris Larano of Dow Jones Newswires, -# but no details] - -# From Paul Eggert (2014-08-14): -# The following source says DST may be instituted November-January and again -# March-June, but this is not definite. It also says DST was last proclaimed -# during the Ramos administration (1992-1998); but again, no details. -# Carcamo D. PNoy urged to declare use of daylight saving time. -# Philippine Star 2014-08-05 -# http://www.philstar.com/headlines/2014/08/05/1354152/pnoy-urged-declare-use-daylight-saving-time + +# From P Chan (2021-05-10): +# Here's a fairly comprehensive article in Japanese: +# https://wiki.suikawiki.org/n/Philippine%20Time +# (2021-05-16): +# According to the references listed in the article, +# the periods that the Philippines (Manila) observed DST or used +9 are: +# +# 1936-10-31 24:00 to 1937-01-15 24:00 +# (Proclamation No. 104, Proclamation No. 126) +# 1941-12-15 24:00 to 1945-11-30 24:00 +# (Proclamation No. 789, Proclamation No. 20) +# 1954-04-11 24:00 to 1954-06-04 24:00 +# (Proclamation No. 13, Proclamation No. 33) +# 1977-03-27 24:00 to 1977-09-21 24:00 +# (Proclamation No. 1629, Proclamation No. 1641) +# 1990-05-21 00:00 to 1990-07-28 24:00 +# (National Emergency Memorandum Order No. 17, Executive Order No. 415) +# +# Proclamation No. 104 ... October 30, 1936 +# https://www.officialgazette.gov.ph/1936/10/30/proclamation-no-104-s-1936/ +# Proclamation No. 126 ... January 15, 1937 +# https://www.officialgazette.gov.ph/1937/01/15/proclamation-no-126-s-1937/ +# Proclamation No. 789 ... December 13, 1941 +# https://www.officialgazette.gov.ph/1941/12/13/proclamation-no-789-s-1941/ +# Proclamation No. 20 ... November 11, 1945 +# https://www.officialgazette.gov.ph/1945/11/11/proclamation-no-20-s-1945/ +# Proclamation No. 13 ... April 6, 1954 +# https://www.officialgazette.gov.ph/1954/04/06/proclamation-no-13-s-1954/ +# Proclamation No. 33 ... June 3, 1954 +# https://www.officialgazette.gov.ph/1954/06/03/proclamation-no-33-s-1954/ +# Proclamation No. 1629 ... March 25, 1977 +# https://www.officialgazette.gov.ph/1977/03/25/proclamation-no-1629-s-1977/ +# Proclamation No. 1641 ...May 26, 1977 +# https://www.officialgazette.gov.ph/1977/05/26/proclamation-no-1641-s-1977/ +# National Emergency Memorandum Order No. 17 ... May 2, 1990 +# https://www.officialgazette.gov.ph/1990/05/02/national-emergency-memorandum-order-no-17-s-1990/ +# Executive Order No. 415 ... July 20, 1990 +# https://www.officialgazette.gov.ph/1990/07/20/executive-order-no-415-s-1990/ +# +# During WWII, Proclamation No. 789 fixed two periods of DST. The first period +# was set to continue only until January 31, 1942. But Manila was occupied by +# the Japanese earlier in the month.... +# +# For the date of the adoption of standard time, Shank[s] gives 1899-05-11. +# The article is not able to state the basis of that. I guess it was based on +# a US War Department Circular issued on that date. +# https://books.google.com/books?id=JZ1PAAAAYAAJ&pg=RA3-PA8 +# +# However, according to other sources, standard time was adopted on +# 1899-09-06. Also, the LMT was GMT+8:03:52 +# https://books.google.com/books?id=MOYIAQAAIAAJ&pg=PA521 +# https://books.google.com/books?id=lSnqqatpYikC&pg=PA21 +# +# From Paul Eggert (2024-09-05): +# The penultimate URL in P Chan's email refers to page 521 of +# Selga M, The Time Service in the Philippines. +# Proc Pan-Pacific Science Congress. Vol. 1 (1923), 519-532. +# It says, "The change from the meridian 120° 58' 04" to the 120th implied a +# change of 3 min. 52s.26 in time; consequently on 6th September, 1899, +# Manila Observatory gave the noon signal 3 min. 52s.26 later than before". +# +# Wikipedia says the US declared Manila liberated on March 4, 1945; +# this doesn't affect clocks, just our time zone abbreviation and DST flag. # From Paul Goyette (2018-06-15) with URLs updated by Guy Harris (2024-02-15): # In the Philippines, there is a national law, Republic Act No. 10535 @@ -3697,24 +3746,26 @@ Zone Asia/Hebron 2:20:23 - LMT 1900 Oct # influence of the sources. There is no current abbreviation for DST, # so use "PDT", the usual American style. -# From P Chan (2021-05-10): -# Here's a fairly comprehensive article in Japanese: -# https://wiki.suikawiki.org/n/Philippine%20Time -# From Paul Eggert (2021-05-10): -# The info in the Japanese table has not been absorbed (yet) below. - # Rule NAME FROM TO - IN ON AT SAVE LETTER/S -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 +Rule Phil 1936 only - Oct 31 24:00 1:00 D +Rule Phil 1937 only - Jan 15 24:00 0 S +Rule Phil 1941 only - Dec 15 24:00 1:00 D +# The following three rules were canceled by Japan: +#Rule Phil 1942 only - Jan 31 24:00 0 S +#Rule Phil 1942 only - Mar 1 0:00 1:00 D +#Rule Phil 1942 only - Jun 30 24:00 0 S +Rule Phil 1945 only - Nov 30 24:00 0 S +Rule Phil 1954 only - Apr 11 24:00 1:00 D +Rule Phil 1954 only - Jun 4 24:00 0 S +Rule Phil 1977 only - Mar 27 24:00 1:00 D +Rule Phil 1977 only - Sep 21 24:00 0 S +Rule Phil 1990 only - May 21 0:00 1:00 D +Rule Phil 1990 only - Jul 28 24:00 0 D # Zone NAME STDOFF RULES FORMAT [UNTIL] -Zone Asia/Manila -15:56:00 - LMT 1844 Dec 31 - 8:04:00 - LMT 1899 May 11 - 8:00 Phil P%sT 1942 May - 9:00 - JST 1944 Nov +Zone Asia/Manila -15:56:08 - LMT 1844 Dec 31 + 8:03:52 - LMT 1899 Sep 6 4:00u + 8:00 Phil P%sT 1942 Feb 11 24:00 + 9:00 - JST 1945 Mar 4 8:00 Phil P%sT # Bahrain diff --git a/zone.tab b/zone.tab index bfc0b593..d2be6635 100644 --- a/zone.tab +++ b/zone.tab @@ -310,7 +310,7 @@ PF -0900-13930 Pacific/Marquesas Marquesas Islands PF -2308-13457 Pacific/Gambier Gambier Islands PG -0930+14710 Pacific/Port_Moresby most of Papua New Guinea PG -0613+15534 Pacific/Bougainville Bougainville -PH +1435+12100 Asia/Manila +PH +143512+1205804 Asia/Manila PK +2452+06703 Asia/Karachi PL +5215+02100 Europe/Warsaw PM +4703-05620 America/Miquelon diff --git a/zone1970.tab b/zone1970.tab index 7726f39a..e7452043 100644 --- a/zone1970.tab +++ b/zone1970.tab @@ -246,7 +246,7 @@ PF -0900-13930 Pacific/Marquesas Marquesas Islands PF -2308-13457 Pacific/Gambier Gambier Islands PG,AQ,FM -0930+14710 Pacific/Port_Moresby Papua New Guinea (most areas), Chuuk, Yap, Dumont d'Urville PG -0613+15534 Pacific/Bougainville Bougainville -PH +1435+12100 Asia/Manila +PH +143512+1205804 Asia/Manila PK +2452+06703 Asia/Karachi PL +5215+02100 Europe/Warsaw PM +4703-05620 America/Miquelon diff --git a/zonenow.tab b/zonenow.tab index 01f536b3..050d8a7d 100644 --- a/zonenow.tab +++ b/zonenow.tab @@ -236,7 +236,7 @@ XX +3114+12128 Asia/Shanghai China ("CST") XX +2217+11409 Asia/Hong_Kong Hong Kong ("HKT") # # +08 - PHT -XX +1435+12100 Asia/Manila Philippines ("PHT") +XX +143512+1205804 Asia/Manila Philippines ("PHT") # # +08 - WITA XX -0507+11924 Asia/Makassar Indonesia ("WITA") -- 2.43.0