Calendrical calculation modules
===============================

There are three independent modules available in this package.


A "Calendar" module
-------------------

This module handles calculations about various calendars.  It is
based on ``Calendrical Calculations'' and ``Calendrical Calcula-
tions, II: Three Historical Calendars''.

This code is modified from the original code.  4 CE is not a leap
year in the Julian calendar, and the Mayan calendar epoch is
September 6, 3114 BCE in the Julian calendar.  Please define "PA-
PER" if you want to get the same results as the original.

In addition to the above, I also wrote code for a few calendars
(I can't assure you that they're right :-p).

This module supports the following calendars:

    Gregorian (current civil), Calendar week (ISO), Julian (old
    civil), Islamic (Moslem), Hebrew (Jewish), Mayan, French Rev-
    olutionary, Old Hindu, Achelis', Coptic, Ethiopian, Jalaali
    (incomplete), Kyureki (Japanese traditional with CE)

NOTE: This module now handles jd and mjd based on "chronological"
sense.


A "Getdate" module
------------------

This module provides a method which creates a Time object re-
flecting the given representation of dates and times.


An "Sdn" module
---------------

This is an interface to the Scott E. Lee's SDN package.

This module supports the following calendars:

    Gregorian, Julian, French Republican, Jewish


Install
-------

Use the script "install.rb".

  $ ruby install.rb config
  $ ruby install.rb setup
 ($ su)
  # ruby install.rb install

For more information, type "ruby install.rb --help".


Acknowledgments
---------------

I thank Edward M. Reingold, Nachum Dershowitz, Stewart M. Clamen
and Scott E. Lee who wrote various calendrical code.


References
----------

Nachum Dershowitz and Edward M. Reingold, ``Calendrical Calcula-
tions'' Software---Practice & Experience, vol. 20, no.  9 (Sept.
1990), pp. 899--928.

Edward M. Reingold, Nachum Dershowitz and Stewart M. Clamen,
``Calendrical Calculations, II: Three Historical Calendars''
Software---Practice & Experience, vol. 23, no. 4 (April. 1993),
pp. 383--404.

koyomi-keisan kenkyu-kai, shin koyomi benricho, koseisha ko-
seikaku, 1991

jusaburo nojima, nihon-reki sei-reki tsuki-hi taisho-hyo, nichi-
gai associates, 1987,1996

koyomi no kai, koyomi no hyakka-jiten, shin jinbutsu oraisha,
1986,1989

masao uchida, nihon rekijitsu genten 4th ed, yuzan kaku,
1975,1992

nichigai associates, 21 seiki-reki, nichigai associates 2000


Tadayoshi Funaba
mailto:tadf@funaba.org
http://www.funaba.org/en/
