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From: Robert A Duff <bobduff@world.std.com>
Subject: Re: Ada Calendar oddity <was Re: C date package>
Date: 2000/05/10
Date: 2000-05-10T00:00:00+00:00	[thread overview]
Message-ID: <wccn1lyjz94.fsf@world.std.com> (raw)
In-Reply-To: slrn8hioca.101.randhol+nospam@kiuk0156.chembio.ntnu.no

randhol+nospam@pvv.org (Preben Randhol) writes:

> I was looking yesterday in the RM and found that Year in the
> Ada.Calendar was defined until 2099 only. I have search on deja, but I
> cannot find any reason for it to be defined only to 2099.

The reason for the range 1901..2099 is that leap year calculations are
simpler (and more efficient) in this range -- in this range, all years
divisible by 4 are leap years (including 2000).  1900 and 2100 are not
leap years.

One can argue about whether that's a *good* reason, but it's the reason.

What range would *you* suggest?

If I were designing such a package, I would think about the number of
bits needed to represent the number of seconds (or nanoseconds?) in the
range.

- Bob




  reply	other threads:[~2000-05-10  0:00 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <l0313030eb53d1408aee7@[144.205.16.58]>
2000-05-09  0:00 ` C date package Geoff Bull
2000-05-09  0:00   ` Geoff Bull
2000-05-09  0:00     ` Robert Dewar
2000-05-10  0:00       ` Geoff Bull
2000-05-10  0:00         ` Robert Dewar
2000-05-10  0:00           ` Ada Calendar oddity <was Re: C date package> Preben Randhol
2000-05-10  0:00             ` Robert A Duff [this message]
2000-05-10  0:00               ` Preben Randhol
2000-05-10  0:00                 ` Charles Hixson
2000-05-11  0:00                   ` Geoff Bull
2000-05-11  0:00                     ` Charles Hixson
2000-05-12  0:00                       ` Geoff Bull
2000-05-17  0:00               ` Robert I. Eachus
2000-05-19  0:00                 ` Geoff Bull
2000-05-19  0:00                   ` Robert I. Eachus
2000-05-21  0:00                     ` Robert Dewar
2000-05-21  0:00                   ` Robert Dewar
     [not found]                     ` <392869F0.D88F056A@acenet.com.au>
2000-05-22  0:00                       ` Tarjei Tj�stheim Jensen
2000-05-27  0:00                         ` Reinert Korsnes
2000-05-27  0:00                           ` Tarjei Tj�stheim Jensen
2000-06-03  0:00                       ` Robert I. Eachus
2000-05-10  0:00             ` Tarjei Tj�stheim Jensen
2000-05-11  0:00               ` Charles Hixson
2000-05-11  0:00                 ` Tarjei Tj�stheim Jensen
2000-05-12  0:00                   ` Charles Hixson
2000-05-12  0:00                     ` Tarjei Tj�stheim Jensen
2000-05-11  0:00               ` Geoff Bull
2000-05-11  0:00                 ` Gautier
2000-05-12  0:00                   ` Geoff Bull
2000-05-12  0:00                     ` Gautier
2000-05-11  0:00                       ` Al Christians
2000-05-10  0:00           ` C date package Ken Garlington
2000-05-10  0:00             ` Geoff Bull
2000-05-10  0:00           ` Geoff Bull
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