jburkardt

DOOMSDAY\ Day of Week for Given Date {#doomsday-day-of-week-for-given-date align=”center”} ==========================

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DOOMSDAY is 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.

Licensing: {#licensing align=”center”}

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages: {#languages align=”center”}

DOOMSDAY is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version and a Python version.

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

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

CALENDAR_RD, a C++ program which computes the representation of a given date in a number of calendrical systems, by Edward Reingold and Nachum Dershowitz

CALPAK, a C++ library which makes various calendar calculations;

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

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

Reference: {#reference align=”center”}

1. Lewis Carroll (Charles Dodgson),\ To Find the Day of the Week for Any Given Date,\ Nature, 31 March 1887.
2. John Conway,\ Tomorrow is the Day After Doomsday,\ Eureka,\ Volume 36, October 1973, pages 28-31.
3. Gary Meisters,\ Lewis Carroll’s Day-of-the-Week Algorithm,\ Math Horizons,\ November 2002, pages 24-25.

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

• doomsday.cpp, the source code.
• doomsday.hpp, the include file.

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

• doomsday_prb.cpp, a sample calling program.
• doomsday_prb_output.txt, the output file.

List of Routines: {#list-of-routines align=”center”}

• DOOMSDAY_GREGORIAN: weekday given any date in Gregorian calendar.
• I4_MAX returns the maximum of two I4’s.
• I4_MIN returns the minimum of two I4’s.
• I4_MODP returns the nonnegative remainder of I4 division.
• I4_WRAP forces an I4 to lie between given limits by wrapping.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• WEEKDAY_TO_NAME_COMMON returns the name of a Common weekday.
• WEEKDAY_VALUES returns the day of the week for various dates.
• YEAR_IS_LEAP_GREGORIAN returns TRUE if the Gregorian year was a leap year.

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

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Last revised on 28 May 2012.