It it now a leap year?

Kevin J. Cummings cummings at kjchome.homeip.net
Thu Aug 9 19:02:12 UTC 2007


Steve Searle wrote:
> Around 01:57am on Thursday, August 09, 2007 (UK time), Karl Larsen scrawled:
> 
>> 	glad you like it. The cal program is VERY powerful.
> 
> Cal is indeed excellent, even showing that the rules defined for leap
> years earlier in this thread are not correct.  If it was as simple as
> divisible by 100 but not divisible by 400 = not leap year then:
> 
> cal 2 1500
> 
> should not show February having 29 days, which it does.
> 
> To get a clue as to why this is correct, try
> 
> cal 9 1752

Which calendar are you expecting for these dates?  Julian or Gregorian?
 Didn't Pope Gregory fixed the calendar (thus it bears his name), but it
wasn't used consistently worldwide until some time in the 18th century.
There is even some question as to whether George Washington's Feb 22
birth date was a Julian date or Gregorian date and he was clearly born
in the 1700's.  It looks like "cal" switches from Julian dates to
Gregorian dates after 9/2/1752.  From the cal man page:

>      The Gregorian Reformation is assumed to have occurred in 1752 on the 3rd of September.  By this time, most countries had recognized the
>      reformation (although a few did not recognize it until the early 1900’s.)  Ten days following that date were eliminated by the reforma-
>      tion, so the calendar for that month is a bit unusual.

-- 
Kevin J. Cummings
kjchome at rcn.com
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)




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