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[124.169.47.98]) by smtp.gmail.com with ESMTPSA id 6-20020a630106000000b004784cdc196dsm2768410pgb.24.2023.01.27.13.14.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Jan 2023 13:14:45 -0800 (PST) Message-ID: <63d43ec5.630a0220.87fac.44e2@mx.google.com> X-Google-Original-Message-ID: --text follows this line-- References: <63c8f5a6.170a0220.ea8cf.7f96@mx.google.com> <63c9b654.170a0220.d82d2.4254@mx.google.com> <87mt6e86sr.fsf@tsdye.online> <63c9d976.620a0220.a7d40.113b@mx.google.com> <87tu0mjb24.fsf@tsdye.online> <63ca1283.170a0220.5bc81.0fdd@mx.google.com> <87pmb9k8oi.fsf@tsdye.online> <3035CDD5-41DD-4516-9E4E-9E0DF16BE2E0@gmail.com> User-agent: mu4e 1.9.17; emacs 29.0.60 From: Tim Cross To: Jean Louis Cc: Sterling Hooten , "Thomas S. 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List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-orgmode-bounces+larch=yhetil.org@gnu.org Sender: emacs-orgmode-bounces+larch=yhetil.org@gnu.org X-Migadu-Country: US X-Migadu-Flow: FLOW_IN ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1674854150; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post:dkim-signature; bh=7aRzF/wd1F8gmH6dN1opjtiTt+yhEcekm8scivFehH8=; b=cFBSWvWKnGSbXHdv0W5tSz8kt8xpD4D/DyEeIKIRIjzNDdAZyghORXxQKT9sIEFSTfUF1d hKeXOqVdWDxS3NVS1BijdKKBTRbuMDRSXTmXwCKXW8wHRB8vxyvAIdUqI6JAXm71VWV8HP xt9hR/NqwuL7f6TIy1/x+x0NGbjzWePMuFuZiJJvIqKjVIaLHaXLNLprTS3qlVMCmCLoy6 2pxQDJJkDWmvm8/aPwbiUHZB90sBKXG7eGAi1TiRXQpXXq40RBeNo1yincxwM2Uq3sNE13 pqAkiHXZlSntg73Sf9kUj0cymF09PqqoHmq/ZBz/12gG/rrpIOFxaY7sh5wJRw== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=pGddQrXg; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (aspmx1.migadu.com: domain of "emacs-orgmode-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="emacs-orgmode-bounces+larch=yhetil.org@gnu.org" ARC-Seal: i=1; s=key1; d=yhetil.org; t=1674854150; a=rsa-sha256; cv=none; b=Z2yuUMcVGWS/pt6ATy4d3N8USqxUM2UcDNLEY+GUBfZF7sTjREG/64/208pZCO1vLR/fM3 Px6t/zVfG2Rh/VlV3+pbRG0iNwJ+2d4Vq960SOcfuXEx6LAQwqbYRV4Gulz8dQihVjTN6w r9+JrV/3bzA1++0oaRrHIUFNfNPrFWZG0BD5qvKP1VlWuJm4m3eiwTHg0U9i6nguKlKusX NMh7SSGXSO375vzFjW+CLXG11hXe5XUu+8kZvQPyrljHORoEzAnTjpNpDDcA9yuHP+KfDi GsrqQYEHMo62zTU16KRNhReRArnIlIkPdAAewrNsIO22L3Z4jWKgacANEHBPrQ== X-Spam-Score: -4.75 X-Migadu-Spam-Score: -4.75 Authentication-Results: aspmx1.migadu.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=pGddQrXg; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (aspmx1.migadu.com: domain of "emacs-orgmode-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="emacs-orgmode-bounces+larch=yhetil.org@gnu.org" X-Migadu-Queue-Id: 7172E12397 X-Migadu-Scanner: scn1.migadu.com X-TUID: GO+FVTvxerE7 Jean Louis writes: > * Sterling Hooten [2023-01-27 09:06]: >> Offset >> Constant duration difference between times of two time scales >> (ISO). i.e., a quantity to combine with a time scale to produce >> a wall time. e.g., Nepal uses a +5:45 offset from the UTC time >> scale. > > I would be careful calling it constant as time offset is changing > depending of daylight saving time. It is not constant. > > Time offset time stamp may be derived from time zone time. I am sure > about this. > > Time zone time stamp cannot be unambiguously derived from time > offset. I am mostly sure about this. > >> What kinds of representations would a calendar system capable of >> handling timezones require? >>=20 >> =E2=80=A2 Instant (fixed) >> =E2=80=A2 This is referring to an unambiguous moment in time >> =E2=80=A2 e.g., 2007-02-03T05:00:00.000Z >> =E2=80=A2 Offset (fixed) >> =E2=80=A2 This captures the idea of "when did it happen for the person= who >> made the observation" >> =E2=80=A2 e.g., 2007-02-03T04:00:00.000+01:00 > > Offset is not that fixed, maybe from viewpoint of storage as maybe it > is considered fixed in it's representation, but you have to keep in > mind that time offset by it's definition is changing itself, suddenly, > depending of daylight saving and time zone. > I think your misinterpreting the intent here. If you specify a timestamp with offset, it is fixed. It does not change with daylight savings or any other change in rules for a time zone. It does not even specify a time zone. While it is true that a specific location may have time zone changes or that the offset from UTC might change as a result of daylight savings, an offset specified in a times stamp does not change and is fixed. This is one of the limitaiton with using offset. I also think it is a mistake (which I've seen others suggest in this thread) to equate an offset as being an abbreviation for a time zone. For example, some have suggested things like +10000 being the same as AEST and both being abbreviations for Australia/Sydney outside of daylight savings periods. I think that is incorrect. +1000 is a fixed offset from UTC and while it may be the same offset used in a time zone abbreviation like AEST or in a full time zone specification like Australia/Sydney, it is not a time zone specification, only an offset for a specific point in time.