From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!feeder.eternal-september.org!news.glorb.com!Xl.tags.giganews.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!nntp.earthlink.com!news.earthlink.com.POSTED!not-for-mail NNTP-Posting-Date: Sun, 01 Nov 2015 09:15:12 -0600 From: Dennis Lee Bieber Newsgroups: comp.lang.ada Subject: Re: A few questions Date: Sun, 01 Nov 2015 10:15:12 -0500 Organization: IISS Elusive Unicorn Message-ID: <27ac3b19q4hd2q360f751g06315ddpo4ej@4ax.com> References: <6e188805-0cac-4739-a6dc-234efd392909@googlegroups.com> X-Newsreader: Forte Agent 6.00/32.1186 X-No-Archive: YES MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 108.68.178.61 X-Trace: sv3-QkHHULnfQ5eRP7p1f/dB/BRDAm/f6jvHbQGFaGviY5Cy5CvDx/Uf3S4If59KlPqUfCNKTU15L4cGxlG!b6kR1KMxwaeMvuUP1GAn+kkVaHEc9Gk44jp56UI2bY2QnfB8UPrYz59uLH5hnuumhflMks+8wH3r!hNoaV4Y2YFQHDXTsFCqV2j5XdOw= X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 X-Original-Bytes: 2320 Xref: news.eternal-september.org comp.lang.ada:28163 Date: 2015-11-01T10:15:12-05:00 List-Id: On Sun, 1 Nov 2015 05:42:16 -0800 (PST), brbarkstrom@gmail.com declaimed the following: >To put it simply, Astronomical Julian Date (and relatives) produces >a uniform time record in seconds, It also makes sure that all dates/times >are reduced to the same time zone at the Greenwich meridian. The usual >IT convention (YYYYMMDD) is non-uniform (for example, Feb. may have 28 >or 29 days - while Jul. always has 31). It would seem that if your >application might move to a geographically distributed environment, >the Julian Date would be sensible. On the other hand, Julian Date is >not readily interpretable to humans. > There's also the minor touch that the "day" rolls over at noon, not midnight. After all, when one's work runs the dark hours, who wants to fiddle with a day change in the middle of one's observations. If the dates don't need to go back too far (Nov 17 1858, Modified Julian Date is usable, and puts the day change back to midnight. As I recall MJD was the reference point used by the VMS operating system. -- Wulfraed Dennis Lee Bieber AF6VN wlfraed@ix.netcom.com HTTP://wlfraed.home.netcom.com/