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=0.1 required=5.0 tests=BAYES_05,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,cfd23c10fd537a80 X-Google-Attributes: gid103376,public From: Geoff Bull Subject: Re: C date package Date: 2000/05/09 Message-ID: <39178DEA.FD2C20FA@research.canon.com.au>#1/1 X-Deja-AN: 620956667 Content-Transfer-Encoding: 7bit References: <39176D85.603D7AEC@research.canon.com.au> X-Accept-Language: en Content-Type: text/plain; charset=us-ascii X-Complaints-To: usenet@research.canon.com.au X-Trace: cass.research.canon.com.au 957844930 1029 203.12.174.227 (9 May 2000 04:02:10 GMT) Organization: Canon Information Systems Research Australia Mime-Version: 1.0 NNTP-Posting-Date: 9 May 2000 04:02:10 GMT Newsgroups: comp.lang.ada Date: 2000-05-09T04:02:10+00:00 List-Id: Geoff Bull wrote: > Dale Stanbrough wrote: > > i would disagree. In the same way that we use GMT as standard for time, Isn't GMT defunct? > > we should be able to come up with a time based system that underlies the > > various views that are needed. Sounds simple, just base time in the primary time standard: TAI (International Atomic Time). Ada.Real_Time is already based on TAI. And then you layer, Gregorian, Julian, Jewish or whatever calendar you want on top of that ? Trouble is people will start arguing about resolution and range. Do we try to cover needs of astronomers, real time programmer's and the rest of us with one time abstraction. The current Ada.Calendar is pretty weak - just reports an implementation defined time - local time on my system. > > > > After all, a date that is 30,000 days ago -is- 30,000 days ago, no matter > > what calendar is used. In a sense this isn't true. 30,000 rotations of the earth is /= 30,000 * 24 * 60 * 60 seconds. The problem with dealing with time and date is that you are mixing up two concepts: the lapse of a number of fixed size seconds (fixed by definition), the lapse of number of varying size days (in terms of number of seconds).