[Aztlan] 2012 and Pre-Columbian Calendars

[Ivan Van Laningham]

Hi All--

On Wed, Jul 1, 2009 at 12:33 PM, Sid Hollander<sid.hollander at gmail.com> wrote:
> In reference to comments made by Lahun Ik 62  ( Baert Georges) in response
> to Lynda Manning-Schwartz
>
>
> "One can convert the Julian dates to the Mesoamerican name-days by simply
> adding the difference between the two calendars. The difference to be added
> increases 1 day each century, because *the Gregorian Calendar does not
> define years divisible by 100 as leap year..... "
> *
> (underline of last 13 words (if it shows) are mine.
>
> The last portion is in error.  Should be 400. All other century ending years
> are leap years.
>

Actually, it is just the opposite.  The Gregorian correction is to
specify that in any 400 year period, there are only 97 leap years
instead of the Julian's 100.  To implement this, *only* century years
evenly divisible by 400 are leap years.

1600 = leap
1700 = regular
1800 = regular
1900 = regular
2000 = leap

That's why the offset between the Julian & Gregorian calendars today
is only 13 days instead of 14.

If you'd like to find out exactly when the Gregorian and Julian
calendars began years, look at the Calendar FAQ, section 2.10:

http://www.tondering.dk/claus/cal/node3.html#SECTION003100000000000000000

Note especially this paragraph:  "It is sometimes claimed that having
the year start on 1 January was part of the Gregorian calendar reform.
This is not true. This myth has probably started because in 1752
England moved the start of the year to 1 January and also changed to
the Gregorian calendar. But in most other countries the two events
were not related. Scotland, for example, changed to the Gregorian
calendar together with England in 1752, but they moved the start of
the year to 1 January in 1600."

Metta,
Ivan
-- 
Ivan Van Laningham
God N Locomotive Works
http://www.pauahtun.org/
http://www.python.org/workshops/1998-11/proceedings/papers/laningham/laningham.html
Army Signal Corps:  Cu Chi, Class of '70
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