jburkardt

CALENDAR_RD\ Calendrical Conversions {#calendar_rd-calendrical-conversions align=”center”} =======================

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CALENDAR_RD is a C++ program which returns information about a given date, by Edward Reingold, Nachum Dershowitz.

The program is interactive. The user enters y, m and d, which represent the year, (numeric) month, and day of a given date. Note that y must be positive. Also note that all dates are implicitly using the Gregorian calendar, extended backwards indefinitely.

Given date = (y,m,d), the program returns

• the weekday;
• the absolute date, that is, the number of days elapsed since the Gregorian date of Sunday, December 31, 1 BC;
• the (month/day/year) date in the Gregorian calendar (this is simply (m,d,y);
• the (month/day/year) date in the Julian calendar;
• the (week/day/year) in the ISO calendar;
• the (month/day/year) date in the Hebrew calendar;
• the (month/day/year) date in the Islamic calendar;

The program halts when a nonpositive value of y is entered.

Licensing: {#licensing align=”center”}

This code is in the public domain, but any use of it should publicly acknowledge its source.

Languages: {#languages align=”center”}

CALENDAR_RD is available in a C++ version.

Related Data and Programs: {#related-data-and-programs align=”center”}

ANALEMMA, a C++ program which evaluates the equation of time, a formula for the difference between the uniform 24 hour day and the actual position of the sun, by Brian Tung.

CALENDAR_NYT, a FORTRAN90 library which shows the correspondence between dates and the New York Times volume and issue number;

CALPAK, a C++ library which converts between dates as computed on various calendars.

DATES, a dataset directory which contains lists of dates in various calendar systems.

DOOMSDAY, a C++ library which is given the year, month and day of a date, and uses John Conway’s doomsday algorithm to determine the corresponding day of the week.

WEEKDAY, a C++ library which determines the day of the week for a given day.

Author: {#author align=”center”}

Edward Reingold, Nachum Dershowitz.

Reference: {#reference align=”center”}

1. Edward Reingold, Nachum Dershowitz,\ Calendrical Calculations: The Millennium Edition,\ Cambridge University Press, 2001,\ ISBN: 0-521-77752-6,\ LC: CE12.R45.
2. Edward Reingold, Nachum Dershowitz,\ Calendrical Calculations I,\ Software - Practice and Experience,\ Volume 20, Number 9, September 1990, pages 899-928.\
3. Edward Reingold, Nachum Dershowitz, Stewart Clamen,\ Calendrical Calculations, II: Three Historical Calendars,\ Software - Practice and Experience,\ Volume 23, Number 4, pages 383-404, April 1993.

Source Code: {#source-code align=”center”}

• calendar_rd.cpp, the source code;

Examples and Tests: {#examples-and-tests align=”center”}

• calendar_rd_input.txt, the input file.
• calendar_rd_output.txt, the output file.

You can go up one level to the C++ source codes.

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Last revised on 07 December 2008.