by Alex Ram » Sat, 31 Dec 1994 05:12:57
--
by Wolfgang Steg » Sat, 31 Dec 1994 18:09:00
: > Also, on some UNIX machines, a function exists call 'dysize(int year)' or
: > something like that that returns the number of days in the year passed.
: > (366 for leap years). It should not be used, or else used with a check
: > for years divisible by 400, as it returns 366 when you pass it 2000.
: Or maybe just keep using dysize(), but ask your system vendor to fix
: it where it should be fixed (i.e. in the C library).
: --
2000 IS a leap year. The Gregorian Calendar says:
year % 4 == 0: leap year EXCEPT
year % 100 == 0: no a leap year EXCEPT
year % 400 == 0: leap year !!!
2000 % 400 = 0, so 2000 is a leap year (1900 wasn't).
--
Wolfgang Steger
by De » Mon, 02 Jan 1995 09:56:48
> Also, on some UNIX machines, a function exists call 'dysize(int year)' or
> something like that that returns the number of days in the year passed.
> (366 for leap years). It should not be used, or else used with a check
> for years divisible by 400, as it returns 366 when you pass it 2000.
Del
--
-------------------------------+-------------------------------------
-------------------------------+-------------------------------------
by Randy Chapma » Tue, 03 Jan 1995 06:18:56
> > Also, on some UNIX machines, a function exists call 'dysize(int year)' or
> > something like that that returns the number of days in the year passed.
> > (366 for leap years). It should not be used, or else used with a check
> > for years divisible by 400, as it returns 366 when you pass it 2000.
--Randy Chapman
by David E. Wilens » Tue, 03 Jan 1995 11:33:22
Last I knew it was is leap if (divisible by 4 and not by 100 except for 1000) -
soooo that makes 2000 a leap year.
--
David Wilensky
by Network Computing Solutio » Tue, 03 Jan 1995 13:34:58
The correct rule, is:Quote:>Last I knew it was is leap if (divisible by 4 and not by 100 except for
>1000) - soooo that makes 2000 a leap year.
>--
>David Wilensky
(year / 4) && (!(year/100) || (year/400))
2000 = True (1) && (!True (0) || True (1))
2000 = True (1) && True (1)
2000 = True (1)
--
Unix Systems Engineer |
Network Computing Solutions | "Wisconsin Escapee"
Cary, NC 27511, (919) 380-7550 |
by Christopher L Smi » Wed, 04 Jan 1995 02:23:58
: Hate to break it to you, but 2000 -is- a leap year. 1900 was not, 2100
: won't be. At least, that's what I've always been told.
2000/400=5 1900/400 is not an integer. 2000 is the irregularity - it will
not be a leap year, one of the corrections to our imperfect timesystem we
will have to face.
--
Christopher L. Smith
Yale Divinity School SUNY at Stony Brook (Applied Mathematics)
New Haven, CT Stony Brook, NY
by Byron A Je » Wed, 04 Jan 1995 03:30:47
>: Hate to break it to you, but 2000 -is- a leap year. 1900 was not, 2100
>: won't be. At least, that's what I've always been told.
>2000/400=5 1900/400 is not an integer. 2000 is the irregularity - it will
>not be a leap year, one of the corrections to our imperfect timesystem we
>will have to face.
This isn't hard. In English:
- All non century years divisible by 4 are leap years.
- All century years divisible by 400 are leap years.
- All other years are not leap years.
2000 is a leap year (century year divisible by 400)
1900 isn't a leap year.
2100 isn't a leap year.
I have my first year C students coding this. It isn't rocket science.
BAJ
--
Another random extraction from the mental bit stream of...
Byron A. Jeff - PhD student operating in parallel - And Using Linux!
by Har » Wed, 04 Jan 1995 03:42:45
by Godmar Ba » Wed, 04 Jan 1995 03:42:08
Path: news.cs.utah.edu!cs.utexas.edu!howland.reston.ans.net!newsserver.jvnc.net!y
: Hate to break it to you, but 2000 -is- a leap year. 1900 was not, 2100 2000/400=5 1900/400 is not an integer. 2000 is the irregularity - it will I know we shouldn't continue this discussion, but maybe the following A year is approximately 365.2425 days long, astronomically. In other words, unlike 1700, 1800, and 1900; 2000 will be a Godmar P.S.: the calculation wasn't done on a Pentium.
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: > > (366 for leap years). It should not be used, or else used with a check
: > > for years divisible by 400, as it returns 366 when you pass it 2000.
: won't be. At least, that's what I've always been told.
not be a leap year, one of the corrections to our imperfect timesystem we
will have to face.
explanation helps:
This yields 365.2425 * 400 = 146097 days for 400 years.
365 * 400 is only 146000, so we have to introduce 97
leap days. This was done be declaring the rule that
caused so much misunderstanding.
leap year.
P.P.S.: I realize that this 'proof' is rather a matter of
belief than of science, and I could have proved the
opposite by setting the length to 365.2475.
Oh well, just believe it.
by Dave Schauma » Wed, 04 Jan 1995 03:46:35
Two things:
1. 2000 is a leap year.
2. This is a fine example of a Thread That Will Not Die[tm].
I highly recommend to anyone interested in preserving
their sanity to put "leap year" in their kill file.
-Dave
by Nate Bail » Tue, 03 Jan 1995 14:36:05
This problem seems to be a bit broader than just ANSI-C - What I'mQuote:>The correct rule, is:
> (year / 4) && (!(year/100) || (year/400))
> 2000 = True (1) && (!True (0) || True (1))
> 2000 = True (1) && True (1)
> 2000 = True (1)
Since this is a programming wide issue, I set the followup to comp.programming
Nate
(Still awaiting the creation of comp.lang.c.moderated :)
1. 2000 is not world's end! [was: 2000 *IS* Leap Year Problems (Was: Leap year warning)]
|> [ followups to poster ]
|> > Sorry, you are wrong!
|> >
|> > The next century does not start with January 1, 2000 !!
|> > It starts with January 1, 2001 !!!!
|>
|> Wrong, Valentin. And don't imagine that you are "correcting" somebody
|> when you give your _opinion_.
|>
|> IMO hidebound traditionalists have it wrong _both_ ways: not only are
|> you mathematically wrong -- 0-based counting is superior to 1-based
|> counting and certainly more natural for this purpose -- but neither do
|> you have the rationale of popular convention, since most people feel it
|> begins in 2000.
Strange how many hidebound traditionalists there are, imagine thinking
that a century should have 100 years, next thing you know they'll be
suggesting irrational constants for the ratio of of the diameter of a
circle to its circumference when we all know it is 3.2 :^). Fortunately
mathematics is still beyond the pale for public opion, even in America.
--
Michael Salmon
#include <standard.disclaimer>
#include <witty.saying>
#include <fancy.pseudo.graphics>
Ericsson Telecom AB
Stockholm
3. hardware clock fails 2000 leap year test
4. another disksuite 4.1 question
5. getdate() does not work with leap-years
8. socket in TIME_WAIT state too longly !!!
9. Unix program cal says 1700 is a leap year!
10. Leap Year shell script function
13. Leap year bug in backup system ?