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[220.235.140.148]) by smtp.gmail.com with ESMTPSA id r23-20020a17090b051700b002271f55157bsm12879503pjz.9.2023.01.16.12.36.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Jan 2023 12:36:52 -0800 (PST) Message-ID: <63c5b564.170a0220.fcec8.41dd@mx.google.com> X-Google-Original-Message-ID: --text follows this line-- References: <86zgamtv6o.fsf@gmail.com> <87tu0t1i0c.fsf@localhost> <87mt6ilkyb.fsf@localhost> User-agent: mu4e 1.9.14; emacs 29.0.60 From: Tim Cross To: Ihor Radchenko Cc: Tom Gillespie , emacs-orgmode@gnu.org Subject: Re: [FEATURE REQUEST] Timezone support in org-mode datestamps and org-agenda Date: Tue, 17 Jan 2023 07:32:00 +1100 In-reply-to: <87mt6ilkyb.fsf@localhost> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=2607:f8b0:4864:20::629; envelope-from=theophilusx@gmail.com; helo=mail-pl1-x629.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-orgmode@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "General discussions about Org-mode." 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-Authentication-Results: i=1; aspmx1.migadu.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=XcAe7nFF; 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"; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=key1; d=yhetil.org; t=1673901462; a=rsa-sha256; cv=none; b=d6N7tpr/k2aMygqMPfxJ1F38jDZ23tf06OX32zMA4jE6Mz89n5XihasvD5JYrxillMpiUo 8F1bv2D0csJP6Fc3zUyYc13bOzUCHC9o5o5C17RQZPdqHke+itkLDN1dAyAUFw9cuSr1n7 WSG1gKzaZmUigjOXSOGXTahncmrOAFXQ+NPtxIa5JrdbPqeYQm4TutfdO5VVKCWdLbhWVR pognONUG7xyqKIO8XiMQe7/w4o7LdSFKPRv0vcVxrTLt/uIZqGeBXhRSmqDo+BcOJObuQ8 5Ims7HrWYuvpjzJFWICkTwDCNRif8hdw0ffXdtBJvcdxo7gmQm5rIKLc3GqyPA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1673901462; 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:in-reply-to:in-reply-to: references:references:list-id:list-help:list-unsubscribe: list-subscribe:list-post:dkim-signature; bh=P/7L42KplsxhAT5+pyP1qhOLsfzmVATuKFawNNShC4k=; b=MKh0lfDxJzl9ef8biRJDLRIwyu+cGOLxwV6XTPZQ28dQm3mwHOUVw31Ho8wcII/anMLXCS tBKZFU1CElmK4Go2c2knA62Le/nxqYarN6swAUsuM54t9fvTxkz1EMOIqN5K3GJ7lP0EDY /QmI5Yj5G/+abp7h5p8WXkCdAS4v1m+OuK6z738b46b8by5OoMgEV6RdycsYkMToHL1yi2 Ag4SYbfeXVoeswdGVAOHZ+oX9PqciFLUMMac/Md1Jwxyc6F+1FZsLvPwdTV5uDjXN4lkMk OySWhMgdCTTvMRMiuT97xGg1Vc1HR1YlgD+B/IbzikV/spIWslzOGADbYgvx0Q== X-Migadu-Queue-Id: 5C36F3903A X-Migadu-Scanner: scn0.migadu.com Authentication-Results: aspmx1.migadu.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=XcAe7nFF; 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"; dmarc=pass (policy=none) header.from=gmail.com X-Migadu-Spam-Score: -6.28 X-Spam-Score: -6.28 X-TUID: PITifRT+xn9n Ihor Radchenko writes: > Tom Gillespie writes: > > >> I will note that this doesn't address the issue of syntax for >> historical and future dates. For historical dates those almost always >> require significant additional metadata to compensate for things like >> the julian/gregorian calendar switchover etc. for future dates we may >> want to go ahead and specify something beyond YYYY-. > > This is somewhat orthogonal to time zones. > > I am not sure if julian/gregorian is handled by system time libraries. > It should, no? > > As for years BC, <-0001-...> will be a breaking change. But I do not > think that we need to really worry about this. Not unless we actually > get feature request. What is the practical application? Given that the stated approach is to leverage off OS facilities in this area, it probably should also be noted that some OSs don't handle historical dates, especially BC ones, at all well. For example, some OS use a 32 bit number to represent the date+time and can really only handle dates between approx 1900 and 2038 (or around there - cannot remember specific range). So with respect to timestamps and time related calculations, we are limited by the capabilities of the least capable supported OS.