DOOMSDAY
Day of Week for Given Date
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:
The computer code and data files described and made available on this
web page are distributed under
the GNU LGPL license.
Languages:
DOOMSDAY is available in
a C version and
a C++ version and
a FORTRAN90 version and
a MATLAB version and
a Python version.
Related Data and Programs:
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:

Lewis Carroll (Charles Dodgson),
To Find the Day of the Week for Any Given Date,
Nature, 31 March 1887.

John Conway,
Tomorrow is the Day After Doomsday,
Eureka,
Volume 36, October 1973, pages 2831.

Gary Meisters,
Lewis Carroll's DayoftheWeek Algorithm,
Math Horizons,
November 2002, pages 2425.
Source Code:
Examples and Tests:
List of Routines:

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.
Last revised on 28 May 2012.