From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: =?utf-8?Q?=C3=93scar_Fuentes?= Newsgroups: gmane.emacs.help Subject: Re: Wrong times for sunrise/sunset? Date: Sun, 20 Jan 2019 16:00:32 +0100 Message-ID: <87pnsrv0fj.fsf@telefonica.net> References: <87pnssoeiz.fsf@mbork.pl> NNTP-Posting-Host: ciao.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Trace: ciao.gmane.org 1547996480 69755 195.159.176.228 (20 Jan 2019 15:01:20 GMT) X-Complaints-To: usenet@ciao.gmane.org NNTP-Posting-Date: Sun, 20 Jan 2019 15:01:20 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1.90 (gnu/linux) Cc: Help Gnu Emacs mailing list To: Marcin Borkowski Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Sun Jan 20 16:01:18 2019 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.84_2) (envelope-from ) id 1glEb8-000I7k-1G for geh-help-gnu-emacs@m.gmane.org; Sun, 20 Jan 2019 16:01:18 +0100 Original-Received: from localhost ([127.0.0.1]:40899 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1glEbG-00037c-Q8 for geh-help-gnu-emacs@m.gmane.org; Sun, 20 Jan 2019 10:01:26 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:35057) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1glEac-00037W-NI for help-gnu-emacs@gnu.org; Sun, 20 Jan 2019 10:00:47 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1glEab-0000yC-Jk for help-gnu-emacs@gnu.org; Sun, 20 Jan 2019 10:00:46 -0500 Original-Received: from relayout04.e.movistar.es ([86.109.101.204]:37737 helo=relayout04-redir.e.movistar.es) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1glEab-0000pG-CY for help-gnu-emacs@gnu.org; Sun, 20 Jan 2019 10:00:45 -0500 Original-Received: from sky (141.red-79-151-141.dynamicip.rima-tde.net [79.151.141.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: 981711563@telefonica.net) by relayout04.e.movistar.es (Postfix) with ESMTPSA id 43jHt94gDqz16FM; Sun, 20 Jan 2019 16:00:33 +0100 (CET) In-Reply-To: <87pnssoeiz.fsf@mbork.pl> (Marcin Borkowski's message of "Sat, 19 Jan 2019 16:25:40 +0100") X-CTCH-Score: 0.000 X-CTCH-ScoreCust: 0.000 X-TnetOut-Country: IP: 79.151.141.141 | Country: ES X-TnetOut-Information: AntiSPAM and AntiVIRUS on relayout04 X-TnetOut-MsgID: 43jHt94gDqz16FM.A199A X-TnetOut-SpamCheck: no es spam, Unknown X-TnetOut-From: ofv@wanadoo.es X-TnetOut-Watermark: 1548601236.6599@OWwY7PUQ9jHNoiWvLW49Rg X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 86.109.101.204 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.org gmane.emacs.help:119133 Archived-At: Gmane ate my reply, so reposting by e-mail... Marcin Borkowski writes: > C-u M-x sunrise-sunset (and today's date) says: > > Sat, Jan 19, 2019: Sunrise 7:54am (CET), sunset 4:13pm (CET) at Pozna=C5= =84, > Poland (8:19 hrs daylight) > > > Here are my settings: > > (setq calendar-latitude 52.4) > (setq calendar-longitude 16.917) > (setq calendar-location-name "Pozna=C5=84, Poland") > > > (BTW, if anyone is ever near here, please drop me a line - we might be > able to meet in person;-)). > > And C-u M-: calendar-time-zone says (correctly) 60. > > However, https://www.timeanddate.com/astronomy/poland/poznan (for today) > says: > > Sunrise Today: 07:51=E2=86=91 124=C2=B0 Southeast > Sunset Today: 16:14=E2=86=91 237=C2=B0 Southwest > > I also noticed that other online services give yet other results. > > Anybody knows why the difference(s)? One possible reason is refraction. A cursory look at solar.el gives the impression that refraction is not considered, but the astronomy website you referenced does. This can cause a difference of several minutes. Another possible reason is not using the same geographical point. 20 kilometers to the west or east can result in minutes of difference. However, the difference you observe in sunrise (3 minutes) is quite larger than the diference in sunset (1 minute). At this time of year, this can mean that your position and the position used by the website differ on the N/S axis. Just guessing.