[PROPOSED PATCH] Fix 1948-1966 transitions for Los Angeles
These changes came from research I did to check the historical background behind Assembly Bill 385, which would abolish daylight saving time in California, and which has passed the CA Senate Appropriations Committee's suspense file. See: White JB. Bill letting California end Daylight Saving Time clears key committee. Sacramento Bee 2016-08-11. http://www.sacbee.com/news/politics-government/capitol-alert/article95116732... * NEWS, northamerica (CA): For America/Los_Angeles, correct spring-forward transition times from 02:00 to 02:01 in 1948, from 02:00 to 01:00 in 1950-1966. Correct the fall-back transition date for early 1949 from 1949-01-01 to 1949-01-16. --- NEWS | 7 +++++++ northamerica | 35 ++++++++++++++++++++++++++++++++--- 2 files changed, 39 insertions(+), 3 deletions(-) diff --git a/NEWS b/NEWS index ba26a49..a8479eb 100644 --- a/NEWS +++ b/NEWS @@ -7,6 +7,13 @@ Unreleased, experimental changes New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52. (Thanks to Tim Parenti.) + Changes affecting past time stamps + + For America/Los_Angeles, spring-forward transition times have been + corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in + 1950-1966. The fall-back transition date for early 1949 has been + corrected from 1949-01-01 to 1949-01-16. + Changes affecting code zic no longer generates binary files containing POSIX TZ-like diff --git a/northamerica b/northamerica index 6256f97..c9c2061 100644 --- a/northamerica +++ b/northamerica @@ -413,11 +413,40 @@ Zone America/Denver -6:59:56 - LMT 1883 Nov 18 12:00:04 # north of the Salmon River, and the towns of Burgdorf and Warren), # Nevada (except West Wendover), Oregon (except the northern 3/4 of # Malheur county), and Washington + +# From Paul Eggert (2016-08-19): +# In 1948 California had an electricity shortage. To save electricity, +# in early February PG&E changed power frequency from 60 to 59.5 Hz during +# daylight hours, causing electric clocks to lose six minutes per day. +# (This did not change legal time, and is not part of the data here.) +# See: Ross SA. An energy crisis from the past: Northern California in 1948. +# Working Paper No. 8, Institute of Governmental Studies, UC Berkeley, 1973-11. +# http://escholarship.org/uc/item/8x22k30c +# +# In another measure to save electricity, DST was instituted from 1948-03-14 +# at 02:01 to 1949-01-16 at 02:00, with the governor having the option to move +# the fallback transition earlier. See pages 3-4 of: +# http://clerk.assembly.ca.gov/sites/clerk.assembly.ca.gov/files/archive/Statu... +# Apparently the governor did not exercise the option. +# +# In response: +# +# Governor Warren received a torrent of objecting mail, and it is not too much +# to speculate that the objections to Daylight Saving Time were one important +# factor in the defeat of the Dewey-Warren Presidential ticket in California. +# -- Ross, p 25 +# +# Despite the controversy, in 1949 California voters approved Proposition 12, +# which established DST from April's last Sunday at 01:00 until September's +# last Sunday at 02:00. This was amended by 1962's Proposition 6, which changed +# the fall-back date to October's last Sunday. See: +# http://repository.uchastings.edu/cgi/viewcontent.cgi?article=1501&context=ca... +# http://repository.uchastings.edu/cgi/viewcontent.cgi?article=1636&context=ca... # # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER -Rule CA 1948 only - Mar 14 2:00 1:00 D -Rule CA 1949 only - Jan 1 2:00 0 S -Rule CA 1950 1966 - Apr lastSun 2:00 1:00 D +Rule CA 1948 only - Mar 14 2:01 1:00 D +Rule CA 1949 only - Jan 16 2:00 0 S +Rule CA 1950 1966 - Apr lastSun 1:00 1:00 D Rule CA 1950 1961 - Sep lastSun 2:00 0 S Rule CA 1962 1966 - Oct lastSun 2:00 0 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] -- 2.7.4
It does appear that DST ended in California on 16 Jan instead of 1 Jan 1949. A newspaper arnnouncement of DST ending on 16 Jan 1949 would confirm this. At http://libguides.csuchico.edu/c.php?g=414160&p=2822074 there is a link to a Los Angeles Times Archive 1881 - 1990. Clicking on the link indicates that one must be a University of California at Chico student, faculty, or staff to access it. I might be able to find an astrologer in Chico who can help do this (astrologers are motivated to determine observance of DST for old dates) if nobody else on this list has a way to confirm this date. ----- Original Message ----- From: "Paul Eggert" <eggert@cs.ucla.edu> To: <tz@iana.org> Sent: Friday, August 19, 2016 10:25 PM Subject: [tz] [PROPOSED PATCH] Fix 1948-1966 transitions for Los Angeles
These changes came from research I did to check the historical background behind Assembly Bill 385, which would abolish daylight saving time in California, and which has passed the CA Senate Appropriations Committee's suspense file. See: White JB. Bill letting California end Daylight Saving Time clears key committee. Sacramento Bee 2016-08-11. http://www.sacbee.com/news/politics-government/capitol-alert/article95116732...
* NEWS, northamerica (CA): For America/Los_Angeles, correct spring-forward transition times from 02:00 to 02:01 in 1948, from 02:00 to 01:00 in 1950-1966. Correct the fall-back transition date for early 1949 from 1949-01-01 to 1949-01-16. --- NEWS | 7 +++++++ northamerica | 35 ++++++++++++++++++++++++++++++++--- 2 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/NEWS b/NEWS index ba26a49..a8479eb 100644 --- a/NEWS +++ b/NEWS @@ -7,6 +7,13 @@ Unreleased, experimental changes New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52. (Thanks to Tim Parenti.)
+ Changes affecting past time stamps + + For America/Los_Angeles, spring-forward transition times have been + corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in + 1950-1966. The fall-back transition date for early 1949 has been + corrected from 1949-01-01 to 1949-01-16. + Changes affecting code
zic no longer generates binary files containing POSIX TZ-like diff --git a/northamerica b/northamerica index 6256f97..c9c2061 100644 --- a/northamerica +++ b/northamerica @@ -413,11 +413,40 @@ Zone America/Denver -6:59:56 - LMT 1883 Nov 18 12:00:04 # north of the Salmon River, and the towns of Burgdorf and Warren), # Nevada (except West Wendover), Oregon (except the northern 3/4 of # Malheur county), and Washington + +# From Paul Eggert (2016-08-19): +# In 1948 California had an electricity shortage. To save electricity, +# in early February PG&E changed power frequency from 60 to 59.5 Hz during +# daylight hours, causing electric clocks to lose six minutes per day. +# (This did not change legal time, and is not part of the data here.) +# See: Ross SA. An energy crisis from the past: Northern California in 1948. +# Working Paper No. 8, Institute of Governmental Studies, UC Berkeley, 1973-11. +# http://escholarship.org/uc/item/8x22k30c +# +# In another measure to save electricity, DST was instituted from 1948-03-14 +# at 02:01 to 1949-01-16 at 02:00, with the governor having the option to move +# the fallback transition earlier. See pages 3-4 of: +# http://clerk.assembly.ca.gov/sites/clerk.assembly.ca.gov/files/archive/Statu... +# Apparently the governor did not exercise the option. +# +# In response: +# +# Governor Warren received a torrent of objecting mail, and it is not too much +# to speculate that the objections to Daylight Saving Time were one important +# factor in the defeat of the Dewey-Warren Presidential ticket in California. +# -- Ross, p 25 +# +# Despite the controversy, in 1949 California voters approved Proposition 12, +# which established DST from April's last Sunday at 01:00 until September's +# last Sunday at 02:00. This was amended by 1962's Proposition 6, which changed +# the fall-back date to October's last Sunday. See: +# http://repository.uchastings.edu/cgi/viewcontent.cgi?article=1501&context=ca... +# http://repository.uchastings.edu/cgi/viewcontent.cgi?article=1636&context=ca... # # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER -Rule CA 1948 only - Mar 14 2:00 1:00 D -Rule CA 1949 only - Jan 1 2:00 0 S -Rule CA 1950 1966 - Apr lastSun 2:00 1:00 D +Rule CA 1948 only - Mar 14 2:01 1:00 D +Rule CA 1949 only - Jan 16 2:00 0 S +Rule CA 1950 1966 - Apr lastSun 1:00 1:00 D Rule CA 1950 1961 - Sep lastSun 2:00 0 S Rule CA 1962 1966 - Oct lastSun 2:00 0 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] -- 2.7.4
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On Sat 2016-08-20T09:02:56 -0400, David Cochrane hath writ:
It does appear that DST ended in California on 16 Jan instead of 1 Jan 1949. A newspaper arnnouncement of DST ending on 16 Jan 1949 would confirm this.
LA Times believed it was Jan 1 1948 Dec 9, pg 1 Warren sets Jan 1 to end daylight time Decision announced after conference with power chief Sacramento Dec 8 (AP) California will return to standard time Jan. 1, Gov. Warren decreed today. 1949 Jan 1, pg 1 The correct time is now an hour slow There are 25 hours in today, Jan 1. At 2 a.m. PDT, daylight saving time went out the window, the correct time became 1 a.m. PST and a Jan 2 article down from the SF Chronicle blamed Warren for the Cal Bears losing the Rose Bowl to Northwestern. -- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB 260 Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m
Thank you for the clarificaiton, Steve. I think this makes it clear that the original rule of DST ending on 1 Jan 1949 in California is correct. ----- Original Message ----- From: "Steve Allen" <sla@ucolick.org> To: "Time Zone Database discussion" <tz@iana.org> Sent: Saturday, August 20, 2016 11:05 AM Subject: Re: [tz] [PROPOSED PATCH] Fix 1948-1966 transitions for Los Angeles
On Sat 2016-08-20T09:02:56 -0400, David Cochrane hath writ:
It does appear that DST ended in California on 16 Jan instead of 1 Jan 1949. A newspaper arnnouncement of DST ending on 16 Jan 1949 would confirm this.
LA Times believed it was Jan 1
1948 Dec 9, pg 1 Warren sets Jan 1 to end daylight time Decision announced after conference with power chief Sacramento Dec 8 (AP) California will return to standard time Jan. 1, Gov. Warren decreed today.
1949 Jan 1, pg 1 The correct time is now an hour slow There are 25 hours in today, Jan 1. At 2 a.m. PDT, daylight saving time went out the window, the correct time became 1 a.m. PST
and a Jan 2 article down from the SF Chronicle blamed Warren for the Cal Bears losing the Rose Bowl to Northwestern.
-- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB 260 Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m
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The message was checked by ESET NOD32 Antivirus.
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Steve Allen wrote:
and a Jan 2 article down from the SF Chronicle blamed Warren for the Cal Bears losing the Rose Bowl to Northwestern.
Warren sure was responsible for a lot! Anyway, thanks for checking; as it happens I found a way through the paywall myself and had checked it independently before seeing your email. I installed the attached further patch. A bit off topic, but I particularly like PG&E running electric clocks at 59.5/60 speed during the day, while continuing to run them full speed at night. I assume they didn't have to shut down the power grid to switch frequencies. Perhaps they smoothed the second derivative during the twice-daily transitions, as Google does with its smeared leap seconds nowadays? As I write this the power line frequency in Los Angeles is about 59.98 Hz, but over the day it should average out to 60 Hz due to time error correction. If California wanted to switch to 59.5 Hz today, I assume that it'd be a bigger deal than it was back in 1948.
participants (3)
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David Cochrane -
Paul Eggert -
Steve Allen