On 2017-06-10 21:15, Paul Eggert wrote:
.... However, the the question is whether America/Sitka should record the time kept by those in formal control of Sitka, or the time kept by Toomas Ahllund and his fellow workers who made the transition on Sunday in order to have a longer weekend. If the former, the transition should be at 15:30 Friday (Gregorian); if the latter, it should presumably be at 00:00 Sunday (Gregorian). I chose the former, partly because it reflects formal transfer of control, and partly because we have a specific time-of-day recorded for it.
I agree that we need an estimate for the precise instant of the jump by 24 h in the Alaskan time scales near 1867-10-18, as long as we do not have evidence, such as from port diaries. What worries me a bit are the underlying assumptions of the new estimate: • an odd time (1867-10-19T00:31:13Z) of a local event in Sitka is certainly not the effective time of an international treaty like the Alaska purchase; • assumptions that the day of the week was set back from Saturday to Friday at 15:30 or at 15:33:32 local time are unlikely to be true -- such things are done over night; • the assumption that various remote places in Alaska in 1867, not connected by telegraphy lines, would have spent any effort to synchronize some of their actions seems unlikely to me. They had no reason to do it, and they would have needed several days on sea to even agree on the event to be synchronized. That is why I prefer the previous estimate: do the switch at some local midnight close to the date of the purchase. To make this post a bit more productive, here are the implications of what the 2001 "Alaska History" [AH] page by Frank Norris says about Juneau before 1969: Zone America/Juneau 15:02:19 - LMT 1867 Oct 19 15:33:32 -8:57:41 - LMT 1900 Aug 20 12:00 # [AH] "The implementation of a telegraph system, in practical terms, # demanded the establishment of one or more time zones, and # given the concentration of economic and political power at # the time in Alaska’s southeastern panhandle, it was unsurprising # that “Alaska Standard Time,” established in 1900, would be # centered on the 135th meridian, just one hour before Pacific # Standard Time.(6) # (6) Annual Report of the Governor of Alaska, 1901, 73." - -8:00 - PST 1942 + -9:00 - YST 1933 May 24 # [AH] "In May 1933, Seattle launched a new daylight saving time experiment. # In reaction, Juneau city council member J. B. Burford presented a # daylight saving time petition “signed by many business people.” # ..[T]he council unanimously adopted Burford’s plan, and Juneau # went on daylight saving time from May 24 through September 20.(11) # (11) Daily Alaska Empire, May 6, 19-20, and 24, 1933 and September 20, 1933." + -9:00 1:00 YDT 1933 Sep 24 + -9:00 - YST 1940 Apr 30 23:00 # [AH] "On April 2, 1940, voters in the Juneau-Douglas area adopted the # time-change move on a 753-564 vote, and at 11 p.m. on April 30, # area clocks shifted an hour ahead. Other Southeast communities # apparently followed suit, and by the eve of World War II nearly # all of Southeast, except Skagway and Yakutat, had adopted Pacific Time.(13) # 13. Daily Alaska Empire, May 20, June 6, and July 6-8 and 22, 1939, and April 3 and 30, 1940." + -8:00 - PST 1942 Feb 09 02:00 # [AH] "On February 9, 1942, Alaska, along with the other states and # territories, went on daylight saving time or “war time” on a # year-round basis. Because many southeastern communities had moved to # Pacific Time in 1940, adopting federally mandated war time in those # communities brought no changes to local clocks." - -8:00 US P%sT 1946 + -9:00 1:00 YWT 1945 Aug 14 23:00u + -9:00 1:00 YPT 1945 Sep 30 02:00 -8:00 - PST 1969 Michael Deckers.