calpak

calpak, an Octave code which computes various simple calendrical quantities. It can work with various calendars including Egyptian, English, French Revolutionary, Gregorian, Julian, and Julian Ephemeris Date. It can convert a date from one calendar to another. It can return the day of the week for a given date. It can convert from day-number/year to day/month/year format. It can calculate the time difference between two dates.

Some common methods of marking the date include:

• JED, the Julian Ephemeris Date, a count of days since a long time ago;
• YMD, for "year, month, day";
• YJ, for "year, day number".

While there have been many calendars over the years, it is instructive to contemplate just the crazy story of our current "common" calendar. To this day, people disagree about whether there was a year 0, although the Julian calendar was a Roman invention, and Dionysius Exiguus, who gets the blame for shifting the Julian calendar's starting date to the birth year of Christ four hundred years afterwards, didn't have an accurate idea of when that was.

There was a controversial shift from the Julian to the Gregorian calendar, which took place piecemeal throughout the Catholic world, with several countries actually switching back and forth more than once, and with England holding out on the old system until after George Washington was born (which means he was born on February 11 AND February 22).

People didn't agree on when the year started, so that January and February, in particular, were a little murky about which year they belonged to, and the year sometimes started around March 22, near the vernal equinox.

There are a number of side issues, including

• determining the day of the week of a given date;
• determining the number of days between two dates;
• the computation of the date of certain holidays;

Licensing:

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

Languages:

calpak is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.

Related Data and Programs:

calpak_test

calendar_nyt, an Octave code which shows the correspondence between dates and the New York Times volume and issue number;

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

doomsday, an Octave code 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, an Octave code which determines the day of the week for a given day.

weekday_zeller, an Octave code which uses Zeller's congruence to determine the day of the week corresponding to a given date, such as 13 July 1989, Gregorian calendar, ... which was a Thursday.

Reference:

1. Anonymous,
   A Correction; Welcome to 51,254,
   The New York Times,
   01 January 2000, Volume 149, Issue 51254.
2. James Barron,
   What's in a Number? 143 Years of News,
   The New York Times,
   14 March 1995, Volume 144, Issue 50000.
3. Bonnie Blackburn, Leofranc Holford-Stevens,
   The Oxford Companion to the Year,
   Oxford, 1999,
   ISBN: 0192142313,
   LC: CE73.B553.
4. Lewis Carroll (Charles Dodgson),
   To Find the Day of the Week for Any Given Date,
   Nature, 31 March 1887.
5. John Conway,
   Tomorrow is the Day After Doomsday,
   Eureka,
   Volume 36, October 1973, pages 28-31.
6. Peter Duffett-Smith,
   Practical Astronomy With Your Calculator,
   Third Edition,
   Cambridge University Press, 1996,
   ISBN: 0-521-35699-7,
   LC: QB62.5.D83.
7. Donald Knuth,
   The Art of Computer Programming,
   Volume 1, Fundamental Algorithms,
   Third Edition,
   Addison-Wesley, 1997,
   ISBN: 0201896834,
   LC: QA76.6.K64.
8. Donald Knuth,
   The Calculation of Easter,
   Communications of the ACM,
   Volume 5, Number 4, April 1962, pages 209-210.
9. Gary Meisters,
   Lewis Carroll's Day-of-the-Week Algorithm,
   Math Horizons,
   November 2002, pages 24-25.
10. Lance Latham,
    Standard C Date/Time Library,
    Programming the World's Calendars and Clocks,
    Miller Freeman, 1998,
    ISBN: 0-87930-496-0.
11. The New York Times,
    Page One, 1896-1996, A Special Commemorative Edition Celebrating the 100th Anniversary of the Purchase of the New York Times by Adolph S Ochs,
    Galahad Books, 1996,
    ISBN: 0-88365-961-1,
    LC: D411.P25.
12. The New York Times,
    The Complete First Pages, 1851-2008,
    Black Dog & Leventhal Publishers, 2008,
    ISBN13: 978-1-57912-749-7,
    LC: D351.N53.
13. Thomas OBeirne,
    Puzzles and Paradoxes,
    Oxford University Press, 1965,
    LC: QA95.O2.
14. Frank Parise, editor,
    The Book of Calendars,
    Gorgias, 2002,
    ISBN: 1931956766,
    LC: CE11.K4.
15. William Press, Brian Flannery, Saul Teukolsky, William Vetterling,
    Numerical Recipes in FORTRAN: The Art of Scientific Computing,
    Second Edition,
    Cambridge University Press, 1992,
    ISBN: 0-521-43064-X,
    LC: QA297.N866.
16. Edward Reingold, Nachum Dershowitz,
    Calendrical Calculations: The Millennium Edition,
    Cambridge University Press, 2001,
    ISBN: 0-521-77752-6,
    LC: CE12.R45.
17. Edward Reingold, Nachum Dershowitz,
    Calendrical Calculations I,
    Software - Practice and Experience,
    Volume 20, Number 9, September 1990, pages 899-928.
    
18. 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.
19. Edward Richards,
    Mapping Time, The Calendar and Its History,
    Oxford, 1999,
    ISBN: 0-19-850413-6,
    LC: CE11.R5.
20. Ian Stewart,
    Easter is a Quasicrystal,
    Scientific American,
    Volume 284, Number 3, March 2001, pages 80-83.
21. Daniel Zwillinger, editor,
    CRC Standard Mathematical Tables and Formulae,
    30th Edition,
    CRC Press, 1996,
    ISBN: 0-8493-2479-3,
    LC: QA47.M315.

Source Code:

• ch_cap.m, capitalizes a single character.
• cws_to_jed_gps.m, converts a GPS CWS date to a JED.
• cws_to_s_gps.m, writes a GPS CWS date into a string.
• datenum_to_jed.m, converts a MATLAB date number to a JED.
• day_borrow_alexandrian.m, borrows days from months in an Alexandrian date.
• day_borrow_common.m, borrows days from months in a Common date.
• day_borrow_eg_civil.m, borrows days from months in an Egyptian Civil date.
• day_borrow_english.m, borrows days from months in an English date.
• day_borrow_gregorian.m, borrows days from months in a Gregorian date.
• day_borrow_hebrew.m, borrows days from months in a Hebrew date.
• day_borrow_islamic.m, borrows days from months in an Islamic date.
• day_borrow_julian.m, borrows days from months in a Julian date.
• day_borrow_republican.m, borrows days from months in a Republican date.
• day_borrow_roman.m, borrows days from months in a Roman date.
• day_carry_alexandrian.m, carries days to months in an Alexandrian date.
• day_carry_common.m, carries days to months in a Common date.
• day_carry_eg_civil.m, carries days to months in an Egyptian Civil date.
• day_carry_gregorian.m, carries days to months in a Gregorian date.
• day_carry_hebrew.m, carries days to months in a Hebrew date.
• day_carry_islamic.m, carries days to months in an Islamic date.
• day_carry_julian.m, carries days to months in a Julian date.
• day_carry_republican.m, carries days to months in a Republican date.
• day_carry_roman.m, carries days to months in a Roman date.
• day_list_common.m, prints a list of days between two dates.
• days_before_month_common.m, returns the number of days before a Common month.
• days_before_month_gregorian.m, returns the number of days before a Gregorian month.
• days_before_month_julian.m, returns the number of days before a Julian month.
• deflate_common.m, "deflates" dates in the Common Calendar transition month.
• deflate_english.m, "deflates" dates in the English Calendar transition month.
• easter_ds.m, computes the month and day of Easter for a Gregorian year.
• easter_egr.m, computes the month and day of Easter for a Common year.
• easter_egr2.m, computes the month and day of Easter for a Common year.
• easter_julian.m, computes the month and day of Easter for a Julian year.
• easter_julian2.m, computes the month and day of Easter for a Julian year.
• easter_knuth.m, computes the month and day of Easter for a Gregorian year.
• easter_stewart.m, computes the month and day of Easter for a Gregorian year.
• epoch_to_jed_akbar.m, returns the epoch of the Akbar calendar as a JED.
• epoch_to_jed_alexandrian.m, returns the epoch of the Alexandrian calendar as a JED.
• epoch_to_jed_armenian.m, returns the epoch of the Armenian calendar as a JED.
• epoch_to_jed_bahai.m, returns the epoch of the Bahai calendar as a JED.
• epoch_to_jed_bessel.m, returns the epoch of the Bessel calendar as a JED.
• epoch_to_jed_byzantine.m, returns the epoch of the Byzantine calendar as a JED.
• epoch_to_jed_chinese.m, returns the epoch of the Chinese calendar as a JED.
• epoch_to_jed_common.m, returns the epoch of the Common calendar as a JED.
• epoch_to_jed_coptic.m, returns the epoch of the Coptic calendar as a JED.
• epoch_to_jed_deccan.m, returns the epoch of the Deccan calendar as a JED.
• epoch_to_jed_eg_civil.m, returns the epoch of the Egyptian Civil calendar as a JED.
• epoch_to_jed_eg_lunar.m, returns the epoch of the Egyptian Lunar calendar as a JED.
• epoch_to_jed_english.m, returns the epoch of the English calendar as a JED.
• epoch_to_jed_ethiopian.m, returns the epoch of the Ethiopian calendar as a JED.
• epoch_to_jed_gps.m, returns the epoch of the GPS calendar as a JED.
• epoch_to_jed_greek.m, returns the epoch of the Greek calendar as a JED.
• epoch_to_jed_gregorian.m, returns the epoch of the Gregorian calendar as a JED.
• epoch_to_jed_hebrew.m, returns the epoch of the Hebrew calendar as a JED.
• epoch_to_jed_hindu_lunar.m, returns the epoch of the Hindu Lunar calendar as a JED.
• epoch_to_jed_hindu_solar.m, returns the epoch of the Hindu Solar calendar as a JED.
• epoch_to_jed_islamic_a.m, returns the epoch of the Islamic A calendar as a JED.
• epoch_to_jed_islamic_b.m, returns the epoch of the Islamic B calendar as a JED.
• epoch_to_jed_jed.m, returns the epoch of the JED calendar as a JED.
• epoch_to_jed_jelali.m, returns the epoch of the Jelali calendar as a JED.
• epoch_to_jed_julian.m, returns the epoch of the Julian calendar as a JED.
• epoch_to_jed_khwarizmian.m, returns the epoch of the Khwarizmian calendar as a JED.
• epoch_to_jed_macedonian.m, returns the epoch of the Macedonian calendar as a JED.
• epoch_to_jed_matlab.m, epoch of the "MATLAB calendar" as a JED.
• epoch_to_jed_mayan_long.m, returns the epoch of the Mayan Long calendar as a JED.
• epoch_to_jed_mjd.m, returns the epoch of the Modified Julian Day calendar as a JED.
• epoch_to_jed_nyt.m, returns the epoch of the New York Times calendar as a JED.
• epoch_to_jed_persian.m, returns the epoch of the Persian calendar as a JED.
• epoch_to_jed_persian_solar.m, returns the epoch of the Persian Solar calendar as a JED.
• epoch_to_jed_rd.m, returns the epoch of the RD calendar as a JED.
• epoch_to_jed_republican.m, returns the epoch of the French Republican calendar as a JED.
• epoch_to_jed_roman.m, returns the epoch of the calendar as a JED.
• epoch_to_jed_saka.m, returns the epoch of the calendar as a JED.
• epoch_to_jed_soor_san.m, returns the epoch of the calendar as a JED.
• epoch_to_jed_syrian.m, returns the epoch of the calendar as a JED.
• epoch_to_jed_unix.m, returns the epoch of the Unix calendar as a JED.
• epoch_to_jed_y2k.m, returns the epoch of the Y2K calendar as a JED.
• epoch_to_jed_zoroastrian.m, returns the epoch of the Zoroastrian calendar as a JED.
• frac_borrow_common.m, borrows fractions from days in a Common YMDF date.
• frac_borrow_english.m, borrows fractions from days in an English YMDF date.
• frac_borrow_gregorian.m, borrows fractions from days in a Gregorian YMDF date.
• frac_borrow_hebrew.m, borrows fractions from days in a Hebrew YMDF date.
• frac_borrow_islamic.m, borrows fractions from days in an Islamic YMDF date.
• frac_borrow_julian.m, borrows fractions from days in a Julian YMDF date.
• frac_borrow_republican.m, borrows fractions from days in a Republican YMDF date.
• frac_borrow_roman.m, borrows fractions from days in a Roman YMDF date.
• frac_carry_common.m, carries fractions to days in a Common YMDF date.
• frac_carry_english.m, carries fractions to days in an English YMDF date.
• frac_carry_gregorian.m, carries fractions to days in a Gregorian YMDF date.
• frac_carry_hebrew.m, carries fractions to days in a Hebrew YMDF date.
• frac_carry_islamic.m, carries fractions to days in a Hebrew YMDF date.
• frac_carry_republican.m, carries fractions to days in a Republican YMDF date.
• frac_carry_roman.m, carries fractions to days in a Roman YMDF date.
• frac_to_hms.m, converts a fractional day into hours, minutes, seconds.
• frac_to_s.m, writes a positive fraction into a left justified character string.
• hms_to_s.m, writes an HMS date into a string.
• hour_borrow_common.m, borrows a day of hours.
• hour_carry_common.m, carries a day of hours.
• i4_modp.m, returns the positive remainder when I is divided by J.
• i4_to_a.m, returns the I-th alphabetic character.
• i4_to_roman.m, converts an integer to a string of Roman numerals.
• i4_wrap.m, forces an integer to lie between given limits by wrapping.
• inflate_common.m, "inflates" dates in the Common Calendar transition month.
• inflate_english.m, "inflates" dates in the English Calendar transition month.
• j_borrow_common.m, borrows year-days from years in a Common date.
• j_borrow_english.m, borrows year-days from years in an English date.
• j_borrow_gregorian.m, borrows year-days from years in a Gregorian date.
• j_borrow_hebrew.m, borrows year-days from years in a Hebrew date.
• j_borrow_islamic.m, borrows year-days from years in an Islamic date.
• j_borrow_julian.m, borrows year-days from years in a Julian date.
• j_borrow_republican.m, borrows year-days from years in a Republican date.
• j_borrow_roman.m, borrows year-days from years in a Roman date.
• j_carry_common.m, carries year-days to years in a Common date.
• j_carry_english.m, carries year-days to years in a English date.
• j_carry_gregorian.m, carries year-days to years in a Gregorian date.
• j_carry_hebrew.m, carries year-days to years in a Hebrew date.
• j_carry_islamic.m, carries year-days to years in an Islamic date.
• j_carry_julian.m, carries year-days to years in a Julian date.
• j_carry_republican.m, carries year-days to years in a Republican date.
• j_carry_roman.m, carries year-days to years in a Roman date.
• jed_check.m, checks a Julian Ephemeris Date.
• jed_test.m, returns some "interesting" JED's.
• jed_to_cws_gps.m, converts a JED to a GPS CWS date.
• jed_to_datenum.m, converts a JED to a MATLAB datenumber.
• jed_to_mayan_long.m, converts a JED to a Mayan long count date.
• jed_to_mayan_round.m, converts a JED to a Mayan round count date.
• jed_to_mjd.m, converts a JED to a modified JED.
• jed_to_nearest_noon.m, converts a JED to the JED of the nearest noon.
• jed_to_next_noon.m, converts a JED to the JED of the next noon.
• jed_to_nyt.m, converts a JED to a New York Times date.
• jed_to_rd.m, converts a JED to an RD.
• jed_to_ss_unix.m, converts a JED to a UNIX SS date.
• jed_to_weekday.m, computes the day of the week from a JED.
• jed_to_weekday_test.m
• jed_to_year_hebrew.m, the year in the Hebrew calendar when a JED occurred.
• jed_to_yearcount_bessel.m, converts a JED to a Bessel year count.
• jed_to_yearcount_julian.m, converts a JED to a Julian year count.
• jed_to_yjf_common.m, converts a JED to a Common YJF date.
• jed_to_yjf_english.m, converts a JED to an English YJF date.
• jed_to_yjf_gregorian.m, converts a JED to a Gregorian YJF date.
• jed_to_yjf_hebrew.m, converts a JED to a Hebrew YJF date.
• jed_to_yjf_islamic_a.m, converts a JED to an Islamic A YJF date.
• jed_to_yjf_islamic_b.m, converts a JED to an Islamic B YJF date.
• jed_to_yjf_julian.m, converts a JED to a Julian YJF date.
• jed_to_yjf_republican.m, converts a JED to a Republican YJF date.
• jed_to_yjf_roman.m, converts a JED to a Roman YJF date.
• jed_to_ymdf_alexandrian.m, converts a JED to an Alexandrian YMDF date.
• jed_to_ymdf_armenian.m, converts a JED to an Armenian YMDF date.
• jed_to_ymdf_bahai.m, converts a JED to a Bahai YMDF date.
• jed_to_ymdf_common.m, converts a JED to a Common YMDF date.
• jed_to_ymdf_coptic.m, converts a JED to a Coptic YMDF date.
• jed_to_ymdf_eg_civil.m, converts a JED to an Egyptian Civil YMDF date.
• jed_to_ymdf_eg_lunar.m, converts a JED to an Egyptian Lunar YMDF date.
• jed_to_ymdf_english.m, converts a JED to an English YMDF date.
• jed_to_ymdf_ethiopian.m, converts a JED to an Ethiopian YMDF date.
• jed_to_ymdf_gregorian.m, converts a JED to a Gregorian YMDF date.
• jed_to_ymdf_gregorian2.m, converts a JED to a Gregorian YMDF date.
• jed_to_ymdf_hebrew.m, converts a JED to a Hebrew YMDF date.
• jed_to_ymdf_hindu_solar.m, converts a JED to a Hindu Solar YMDF date.
• jed_to_ymdf_islamic_a.m, converts a JED to an Islamic A YMDF date.
• jed_to_ymdf_islamic_b.m, converts a JED to an Islamic B YMDF date.
• jed_to_ymdf_jelali.m, converts a JED to a Jelali YMDF date.
• jed_to_ymdf_julian.m, converts a JED to a Julian YMDF date.
• jed_to_ymdf_julian2.m, converts a JED to a Julian YMDF date.
• jed_to_ymdf_julian3.m, converts a JED to a Julian YMDF date.
• jed_to_ymdf_khwarizmian.m, converts a JED to a Khwarizmian YMDF date.
• jed_to_ymdf_macedonian.m, converts a JED to a Macedonian YMDF date.
• jed_to_ymdf_persian.m, converts a JED to a Persian YMDF date.
• jed_to_ymdf_republican.m, converts a JED to a Republican YMDF date.
• jed_to_ymdf_roman.m, converts a JED to a Roman YMDF date.
• jed_to_ymdf_saka.m, converts a JED to a Saka YMDF date.
• jed_to_ymdf_soor_san.m, converts a JED to a Soor San YMDF date.
• jed_to_ymdf_syrian.m, converts a JED to a Syrian YMDF date.
• jed_to_ymdf_zoroastrian.m, converts a JED to a Zoroastrian YMDF date.
• jed_weekday_values.m, returns weekday indices of selected JED's.
• mayan_long_to_jed.m, converts a Mayan Long Count to a JED.
• mayan_round_to_jed.m, converts a Mayan Round date to a JED.
• minute_borrow_common.m, borrows an hour of minutes on the Common calendar.
• minute_carry_common.m, carries an hour of minutes on the Common calendar.
• mjd_to_jed.m, converts a modified JED to a JED.
• month_borrow_alexandrian.m, borrows a year of months on the Alexandrian calendar.
• month_borrow_bahai.m, borrows a year of months on the Bahai calendar.
• month_borrow_common.m, borrows a year of months on the Common calendar.
• month_borrow_eg_civil.m, borrows a year of months on the Egyptian Civil calendar.
• month_borrow_english.m, borrows a year of months on the English calendar.
• month_borrow_gregorian.m, borrows a year of months on the Gregorian calendar.
• month_borrow_hebrew.m, borrows a year of months on the Hebrew calendar.
• month_borrow_islamic.m, borrows a year of months on the Islamic calendar.
• month_borrow_julian.m, borrows a year of months on the Julian calendar.
• month_borrow_republican.m, borrows a year of months on the Republican calendar.
• month_borrow_roman.m, borrows a year of months on the Roman calendar.
• month_cal_common.m, prints a Common month calendar.
• month_cal_english.m, prints an English month calendar.
• month_cal_gregorian.m, prints a Gregorian month calendar.
• month_cal_hebrew.m, prints a Hebrew month calendar.
• month_cal_islamic_a.m, prints an Islamic A month calendar.
• month_cal_julian.m, prints a Julian month calendar.
• month_cal_republican.m, prints a Republican month calendar.
• month_cal_roman.m, prints a Roman month calendar.
• month_cal_store_common.m, stores a Common calendar into a data structure.
• month_carry_common.m, carries a year of months on the Common calendar.
• month_carry_gregorian.m, carries a year of months on the Gregorian calendar.
• month_carry_alexandrian.m, carries a year of months on the Alexandrian calendar.
• month_carry_bahai.m, carries a year of months on the Bahai calendar.
• month_carry_common.m, carries a year of months on the Common calendar.
• month_carry_eg_civil.m, carries a year of months on the Egyptian Civil calendar.
• month_carry_english.m, carries a year of months on the English calendar.
• month_carry_gregorian.m, carries a year of months on the Gregorian calendar.
• month_carry_hebrew.m, carries a year of months on the Hebrew calendar.
• month_carry_islamic.m, carries a year of months on the Islamic calendar.
• month_carry_julian.m, carries a year of months on the Julian calendar.
• month_carry_republican.m, carries a year of months on the Republican calendar.
• month_carry_roman.m, carries a year of months on the Roman calendar.
• month_length_alexandrian.m, returns the number of days in an Alexandrian month.
• month_length_bahai.m, returns the number of days in a Bahai month.
• month_length_common.m, returns the number of days in a Common month.
• month_length_coptic.m, returns the number of days in a Coptic month.
• month_length_eg_civil.m, returns the number of days in an Egyptian Civil month.
• month_length_eg_lunar.m, returns the number of days in an Egyptian Lunar month.
• month_length_english.m, returns the number of days in an English month.
• month_length_ethiopian.m, returns the number of days in an Ethiopian month.
• month_length_greek.m, returns the number of days in a Gregorian month.
• month_length_gregorian.m, returns the number of days in a Gregorian month.
• month_length_hebrew.m, returns the number of days in a Hebrew month.
• month_length_hindu_solar.m, returns the number of days in a Hindu Solar month.
• month_length_iranian.m, returns the number of days in an Iranian month.
• month_length_islamic.m, returns the number of days in an Islamic month.
• month_length_julian.m, returns the number of days in a Julian month.
• month_length_lunar.m, returns the number of days in a Lunar month.
• month_length_persian.m, returns the number of days in a Persian month.
• month_length_republican.m, returns the number of days in a Republican month.
• month_length_roman.m, returns the number of days in a Roman month.
• month_length_synodic.m, returns the number of days in a Synodic month.
• month_to_ides_roman.m, returns the day of the Ides of a Roman month.
• month_to_month_name_bahai.m, returns the name of a Bahai month.
• month_to_month_name_common.m, returns the name of a Common month.
• month_to_month_name_common3.m, returns an abbreviation of a Common month name.
• month_to_month_name_coptic.m, returns the name of a Coptic month.
• month_to_month_name_eg_civil.m, returns the name of an Egpytian Civil month.
• month_to_month_name_eg_lunar.m, returns the name of an Egpytian Lunar month.
• month_to_month_name_ethiopian.m, returns the name of an Ethiopian month.
• month_to_month_name_greek.m, returns the name of a Greek month.
• month_to_month_name_hebrew.m, returns the name of a Hebrew month.
• month_to_month_name_hindu_lunar.m, returns the name of a Hindu lunar month.
• month_to_month_name_hindu_solar.m, returns the name of a Hindu solar month.
• month_to_month_name_iranian.m, returns the name of an Iranian month.
• month_to_month_name_islamic.m, returns the name of an Islamic month.
• month_to_month_name_persian.m, returns the name of a Persian month.
• month_to_month_name_republican.m, returns the name of a Republican month.
• month_to_month_name_republican2.m, returns the mock name of a Republican month.
• month_to_month_name_roman.m, returns the name of a Roman month.
• month_to_month_name_soor_san.m, returns the name of a Soor San month.
• month_to_month_name_zoroastrian.m, returns the name of a Zoroastrian month.
• month_to_nones_roman.m, returns the day of the nones of a Roman month.
• moon_phase_to_jed.m, calculates the JED of a moon phase.
• mothers_day.m, returns the date of Mother's Day for a given year.
• new_year_to_jed_hebrew.m, returns the JED of the beginning of a Hebrew year.
• now_to_jed.m, expresses the current date as a JED.
• now_to_yjf_common.m, expresses the current date as a YJF date.
• now_to_ymdf_common.m, expresses the current date as a YMDF date.
• now_to_ymdhms_common.m, expresses the current date as a YMDHMS date.
• nyt_to_jed.m, converts a New York Times date to a JED.
• nyt_to_ymd.m, converts a New York Times date to a YMD date.
• r8_uniform_ab.m, returns a scaled pseudorandom R8.
• r8_uniform_ab_test.m
• rd_to_jed.m, converts RD to JED.
• s_blanks_delete.m, compresses multiple successive blanks to one.
• s_to_hms.m, converts a string into a H:M:S date.
• s_to_ymd_common.m, converts a string into a Y/M/D date.
• s_to_ymdhms_common.m, converts a string into a YMDHMS date.
• second_borrow_common.m, borrows a minute of seconds on the Common calendar.
• second_carry_common.m, carries a minute of seconds on the Common calendar.
• ss_to_jed_unix.m, converts a UNIX SS date to a JED.
• thanksgiving_canada.m, computes Canadian Thanksgiving for a Common year.
• thanksgiving_us.m, computes the date of Thanksgiving (US) for a Common year.
• transition_to_jed_common.m, Common calendar transition as a JED.
• transition_to_jed_english.m, English calendar transition as a JED.
• transition_to_jed_jed.m, JED transition as a JED.
• transition_to_jed_mayan_long.m, Mayan long count calendar transition as a JED.
• weekday_check_common.m, makes sure the Common weekday number is between 1 and 7.
• weekday_to_name_bahai.m, returns the name of a Bahai weekday.
• weekday_to_name_common.m, returns the name of a Common weekday.
• weekday_to_name_common2.m, returns the abbreviated name of a Common weekday.
• weekday_to_name_common3.m, returns the abbreviated name of a Common weekday.
• weekday_to_name_french.m, returns the name of a French weekday.
• weekday_to_name_german.m, returns the name of a German weekday.
• weekday_to_name_hebrew.m, returns the name of a Hebrew weekday.
• weekday_to_name_islamic.m, returns the name of an Islamic weekday.
• weekday_to_name_italian.m, returns the name of an Italian weekday.
• weekday_to_name_republican.m, returns the name of a Republican weekday.
• weekday_to_name_roman.m, returns the name of a Roman weekday.
• y_astronomical_to_common.m, converts an Astronomical year to a Common year.
• y_check_alexandrian.m, checks an Alexandrian Y date.
• y_check_bahai.m, checks a Bahai Y date.
• y_check_common.m, checks a Common Y date.
• y_check_eg_civil.m, checks an Egyptian Civil Y date.
• y_check_english.m, checks an English Y date.
• y_check_greek.m, checks a Gregorian Y date.
• y_check_gregorian.m, checks a Gregorian Y date.
• y_check_hebrew.m, checks a Hebrew Y date.
• y_check_islamic.m, checks an Islamic Y date.
• y_check_julian.m, checks a Julian Y date.
• y_check_republican.m, checks a Republican Y date.
• y_common_to_astronomical.m, converts a Common year to an Astronomical year.
• y_julian_to_roman.m, converts a Julian year to a Roman year.
• y_roman_to_julian.m, converts a Roman year to a Julian year.
• y_to_s.m, converts a year to a string.
• y_to_s_alexandrian.m, converts an Alexandrian year to a string.
• y_to_s_bahai.m, converts a Bahai year to a string.
• y_to_s_common.m, converts a Common year to a string.
• y_to_s_coptic.m, converts a Coptic year to a string.
• y_to_s_eg_civil.m, converts an Egyptian Civil year to a string.
• y_to_s_eg_lunar.m, converts an Egyptian Lunar year to a string.
• y_to_s_english.m, converts an English year to a string.
• y_to_s_ethiopian.m, converts an Ethiopian year to a string.
• y_to_s_greek.m, converts a Greek year to a string.
• y_to_s_gregorian.m, converts a Gregorian year to a string.
• y_to_s_hebrew.m, converts a Hebrew year to a string.
• y_to_s_islamic.m, converts an Islamic year to a string.
• y_to_s_julian.m, converts a Julian year to a string.
• y_to_s_persian.m, converts a Persian year to a string.
• y_to_s_republican.m, converts a Republican year to a string.
• y_to_s_roman.m, converts a Roman year to a string.
• year_is_embolismic_eg_civil.m, TRUE if the Egyptian Civil year was embolismic.
• year_is_embolismic_greek.m, TRUE if the Greek year was embolismic.
• year_is_embolismic_hebrew.m, TRUE if the Hebrew year was embolismic.
• year_is_leap_alexandrian.m, TRUE if the Alexandrian year was a leap year.
• year_is_leap_bahai.m, TRUE if the Bahai year was a leap year.
• year_is_leap_common.m, TRUE if the Common year was a leap year.
• year_is_leap_coptic.m, TRUE if the Coptic year was a leap year.
• year_is_leap_eg_lunar.m, TRUE if the Egyptian Lunar year was a leap year.
• year_is_leap_english.m, TRUE if the English year was a leap year.
• year_is_leap_ethiopian.m, TRUE if the Ethiopian year was a leap year.
• year_is_leap_greek.m, TRUE if the Greek year was a leap year.
• year_is_leap_gregorian.m, TRUE if the Gregorian year was a leap year.
• year_is_leap_iranian.m, TRUE if the Iranian year was a leap year.
• year_is_leap_islamic.m, TRUE if the Islamic year was a leap year.
• year_is_leap_julian.m, TRUE if the Julian year was a leap year.
• year_is_leap_persian.m, TRUE if the Persian year was a leap year.
• year_is_leap_republican.m, TRUE if the Republican year was a leap year.
• year_is_leap_roman.m, TRUE if the Roman year was a leap year.
• year_length_days_alexandrian.m, returns the number of days in an Alexandrian year.
• year_length_days_bahai.m, returns the number of days in a Bahai year.
• year_length_days_common.m, returns the number of days in a Common year.
• year_length_days_coptic.m, returns the number of days in a Coptic year.
• year_length_days_eg_civil.m, returns the number of days in an Egyptian Civil year.
• year_length_days_eg_lunar.m, returns the number of days in an Egyptian Lunar year.
• year_length_days_english.m, returns the number of days in an English year.
• year_length_days_ethiopian.m, returns the number of days in an Ethiopian year.
• year_length_days_greek.m, returns the number of days in a Greek year.
• year_length_days_gregorian.m, returns the number of days in a Gregorian year.
• year_length_days_hebrew.m, returns the number of days in a Hebrew year.
• year_length_days_hindu_solar.m, returns the number of days in a Hindu Solar year.
• year_length_days_islamic.m, returns the number of days in an Islamic year.
• year_length_days_lunar.m, returns the number of days in a Lunar year.
• year_length_days_persian.m, returns the number of days in a Persian year.
• year_length_days_republican.m, returns the number of days in a Republican year.
• year_length_days_roman.m, returns the number of days in a Roman year.
• year_length_days_solar.m, returns the number of days in a Solar year.
• year_length_months_alexandrian.m, returns the number of months in an Alexandrian year.
• year_length_months_bahai.m, returns the number of months in a Bahai year.
• year_length_months_common.m, returns the number of months in a Common year.
• year_length_months_coptic.m, returns the number of months in a Coptic year.
• year_length_months_eg_civil.m, returns the number of months in an Egyptian Civil year.
• year_length_months_eg_lunar.m, returns the number of months in an Egyptian Lunar year.
• year_length_months_english.m, returns the number of months in an English year.
• year_length_months_ethiopian.m, returns the number of months in an Ethiopian year.
• year_length_months_greek.m, returns the number of months in a Greek year.
• year_length_months_gregorian.m, returns the number of months in a Gregorian year.
• year_length_months_hebrew.m, returns the number of months in a Hebrew year.
• year_length_months_hindu_lunar.m, returns the number of months in a Hindu Lunar year.
• year_length_months_hindu_solar.m, returns the number of months in a Hindu Solar year.
• year_length_months_islamic.m, returns the number of months in an Islamic year.
• year_length_months_julian.m, returns the number of months in a Julian year.
• year_length_months_persian.m, returns the number of months in a Persian year.
• year_length_months_republican.m, returns the number of months in a Republican year.
• year_length_months_roman.m, returns the number of months in a Roman year.
• year_to_dominical_common.m, dominical numbers, Common calendar.
• year_to_dominical_gregorian.m, dominical numbers, Gregorian calendar.
• year_to_dominical_julian.m, dominical numbers, Julian calendar.
• year_to_epact_gregorian.m, returns the epact of a Gregorian year.
• year_to_epact_julian.m, returns the epact of a Julian year.
• year_to_golden_number.m, returns the golden number of a Common year.
• year_to_indiction_common.m, returns the indiction number of a Common year.
• year_to_scaliger_common.m, converts a Common year to its Scaliger indices.
• year_to_type_hebrew.m, returns the type of a Hebrew year.
• yj_check_common.m, checks a Common YJ date.
• yj_check_english.m, checks an English YJ date.
• yj_check_gregorian.m, checks a Gregorian YJ date.
• yj_check_hebrew.m, checks a Hebrew YJ date.
• yj_check_islamic.m, checks an Islamic YJ date.
• yj_check_julian.m, checks a Julian YJ date.
• yj_check_republican.m, checks a Republican YJ date.
• yj_check_roman.m, checks a Roman YJ date.
• yj_to_s_common.m, converts a Common YJ date to a string.
• yj_to_s_english.m, converts an English YJ date to a string.
• yjf_check_common.m, checks a Common YJF date.
• yjf_check_english.m, checks an English YJF date.
• yjf_compare.m, compares two YJF dates.
• yjf_dif_common.m, computes the difference, in days, between two YJF dates.
• yjf_swap.m, swaps two YJF dates.
• yjf_to_jed_common.m, converts a Common YJF date to a JED.
• yjf_to_jed_english.m, converts an English YJF date to a JED.
• yjf_to_jed_gregorian.m, converts a Gregorian YJF date to a JED.
• yjf_to_jed_hebrew.m, converts a Hebrew YJF date to a JED.
• yjf_to_jed_islamic_a.m, converts an Islamic A YJF date to a JED.
• yjf_to_jed_islamic_b.m, converts an Islamic B YJF date to a JED.
• yjf_to_jed_julian.m, converts a Julian YJF date to a JED.
• yjf_to_jed_republican.m, converts a Republican YJF date to a JED.
• yjf_to_jed_roman.m, converts a Roman YJF date to a JED.
• yjf_to_s_common.m, writes a Common YJF date into a string.
• yjf_to_s_english.m, writes an English YJF date into a string.
• yjf_to_s_gregorian.m, writes a Gregorian YJF date into a string.
• yjf_to_s_hebrew.m, writes a Hebrew YJF date into a string.
• yjf_to_s_islamic.m, writes an Islamic YJF date into a string.
• yjf_to_s_julian.m, writes a Julian YJF date into a string.
• yjf_to_s_republican.m, writes a Republican YJF date into a string.
• yjf_to_s_roman.m, writes a Roman YJF date into a string.
• yjf_to_weekday_common.m, returns the weekday of a Common YJF date.
• yjf_to_ymdf_common.m, converts a Common date from YJF to YMDF format.
• yjf_to_ymdf_english.m, converts an English date from YJF to YMDF format.
• yjf_to_ymdf_gregorian.m, converts a Gregorian date from YJF to YMDF format.
• yjf_to_ymdf_hebrew.m, converts a Hebrew date from YJF to YMDF format.
• yjf_to_ymdf_islamic.m, converts an Islamic date from YJF to YMDF format.
• yjf_to_ymdf_julian.m, converts a Julian date from YJF to YMDF format.
• yjf_to_ymdf_republican.m, converts a Republican date from YJF to YMDF format.
• yjf_to_ymdf_roman.m, converts a Roman date from YJF to YMDF format.
• yjf_to_ymdhms_common.m, converts a Common date from YJF to YMDHMS format.
• yjf_uniform_common.m, picks a random Common YJF date between two given dates.
• ym_check_alexandrian.m, checks an Alexandrian YM date.
• ym_check_bahai.m, checks a Bahai YM date.
• ym_check_common.m, checks a Common YM date.
• ym_check_eg_civil.m, checks an Egypitan civil YM date.
• ym_check_english.m, checks an English YM date.
• ym_check_gregorian.m, checks a Gregorian YM date.
• ym_check_hebrew.m, checks a Hebrew YM date.
• ym_check_islamic.m, checks an Islamic YM date.
• ym_check_julian.m, checks a Julian YM date.
• ym_check_republican.m, checks a Republican YM date.
• ym_check_roman.m, checks a Roman YM date.
• ym_to_decimal.m, converts a Y/M date to a decimal YM date.
• ymd_check_alexandrian.m, checks an Alexandrian YMD date.
• ymd_check_common.m, checks a Common YMD date.
• ymd_check_eg_civil.m, checks an Egyptian Civil YMD date.
• ymd_check_english.m, checks an English YMD date.
• ymd_check_gregorian.m, checks a Gregorian YMD date.
• ymd_check_hebrew.m, checks a Hebrew YMD date.
• ymd_check_islamic.m, checks an Islamic YMD date.
• ymd_check_julian.m, checks a Julian YMD date.
• ymd_check_republican.m, checks a Republican YMD date.
• ymd_check_roman.m, checks a Roman YMD date.
• ymd_compare.m, compares two YMD dates.
• ymd_dif_common.m, gets the day difference between two Common YMD dates.
• ymd_inc_ymd_common.m, increments a YMD date by a YMD increment.
• ymd_to_decimal.m, converts a YMD date to a Decimal Y.F date.
• ymd_to_jed_common.m, converts a Common YMD date to a JED.
• ymd_to_jed_gregorian.m, converts a Gregorian YMD date to a JED.
• ymd_to_jed_julian.m, converts a Julian YMD date to a JED.
• ymd_to_nyt.m, converts a Common YMD date to New York Times date.
• ymd_to_s_alexandrian.m, writes an Alexandrian YMD date into a string.
• ymd_to_s_common.m, writes a Common YMD date into a string.
• ymd_to_s_eg_civil.m, writes an Egyptian Civil YMD date into a string.
• ymd_to_s_eg_lunar.m, writes an Egyptian Lunar YMD date into a string.
• ymd_to_s_gregorian.m, writes a Gregorian YMD date into a string.
• ymd_to_s_julian.m, writes a Julian YMD date into a string.
• ymd_to_s_numeric.m, writes a YMD date into a string.
• ymd_to_weekday_common.m, returns the weekday of a common YMD date.
• ymdf_check_common.m, checks a Common YMDF date.
• ymdf_check_english.m, checks an English YMDF date.
• ymdf_check_gregorian.m, checks a Gregorian YMDF date.
• ymdf_check_hebrew.m, checks a Hebrew YMDF date.
• ymdf_check_islamic.m, checks an Islamic YMDF date.
• ymdf_check_julian.m, checks a Julian YMDF date.
• ymdf_check_republican.m, checks a Republican YMDF date.
• ymdf_check_roman.m, checks a Roman YMDF date.
• ymdf_compare.m, compares two YMDF dates.
• ymdf_dif_common.m, computes the difference between two Common YMDF dates.
• ymdf_dif_english.m, computes the difference between two English YMDF dates.
• ymdf_dif_ymdf_common.m, computes the YMDF difference between two Common YMDF dates.
• ymdf_inc_common.m, increments the Common YMDF date by the given number of days.
• ymdf_inc_english.m, increments the English YMDF date by the given number of days.
• ymdf_inc_gregorian.m, increments the Gregorian YMDF date by the given number of days.
• ymdf_inc_hebrew.m, increments the Hebrew YMDF date by the given number of days.
• ymdf_inc_islamic.m, increments the Islamic YMDF date by the given number of days.
• ymdf_inc_julian.m, increments the Julian YMDF date by the given number of days.
• ymdf_inc_republican.m, increments the Republican YMDF date by the given number of days.
• ymdf_inc_roman.m, increments the Roman YMDF date by the given number of days.
• ymdf_next_common.m, returns the Common YMDF date of the next day.
• ymdf_next_english.m, returns the English YMDF date of the next day.
• ymdf_next_gregorian.m, returns the Gregorian YMDF date of the next day.
• ymdf_next_hebrew.m, returns the Hebrew YMDF date of the next day.
• ymdf_next_islamic.m, returns the Islamic YMDF date of the next day.
• ymdf_next_julian.m, returns the Julian YMDF date of the next day.
• ymdf_next_republican.m, returns the Republican YMDF date of the next day.
• ymdf_next_roman.m, returns the Roman YMDF date of the next day.
• ymdf_prev_common.m, returns the Common YMDF date of the previous day.
• ymdf_prev_english.m, returns the English YMDF date of the previous day.
• ymdf_prev_gregorian.m, returns the Gregorian YMDF date of the previous day.
• ymdf_prev_hebrew.m, returns the Hebrew YMDF date of the previous day.
• ymdf_prev_islamic.m, returns the Islamic YMDF date of the previous day.
• ymdf_prev_julian.m, returns the Julian YMDF date of the previous day.
• ymdf_prev_republican.m, returns the Republican YMDF date of the previous day.
• ymdf_prev_roman.m, returns the Roman YMDF date of the previous day.
• ymdf_swap.m, swaps two YMDF dates.
• ymdf_to_jed_alexandrian.m, converts an Alexandrian YMDF date to a JED.
• ymdf_to_jed_armenian.m, converts an Armenian YMDF date to a JED.
• ymdf_to_jed_bahai.m, converts a Bahai YMDF date to a JED.
• ymdf_to_jed_common.m, converts a Common YMDF date to a JED.
• ymdf_to_jed_coptic.m, converts a Coptic YMDF date to a JED.
• ymdf_to_jed_eg_civil.m, converts an Egyptian Civil YMDF date to a JED.
• ymdf_to_jed_eg_lunar.m, converts an Egyptian Lunar YMDF date to a JED.
• ymdf_to_jed_english.m, converts an English YMDF date to a JED.
• ymdf_to_jed_ethiopian.m, converts an Ethiopian YMDF date to a JED.
• ymdf_to_jed_gregorian.m, converts a Gregorian YMDF date to a JED.
• ymdf_to_jed_hebrew.m, converts a Hebrew YMDF date to a JED.
• ymdf_to_jed_hindu_solar.m, converts a Hindu Solar YMDF date to a JED.
• ymdf_to_jed_islamic_a.m, converts an Islamic A YMDF date to a JED.
• ymdf_to_jed_islamic_a2.m, converts an Islamic A YMDF date to a JED.
• ymdf_to_jed_islamic_b.m, converts an Islamic B YMDF date to a JED.
• ymdf_to_jed_jelali.m, converts a Jelali YMDF date to a JED.
• ymdf_to_jed_julian.m, converts a Julian YMDF date to a JED.
• ymdf_to_jed_julian2.m, converts a Julian YMDF date to a JED.
• ymdf_to_jed_khwarizmian.m, converts a Khwarizmian YMDF date to a JED.
• ymdf_to_jed_macedonian.m, converts a Macedonian YMDF date to a JED.
• ymdf_to_jed_persian.m, converts a Persian YMDF date to a JED.
• ymdf_to_jed_republican.m, converts a Republican YMDF date to a JED.
• ymdf_to_jed_roman.m, converts a Roman YMDF date to a JED.
• ymdf_to_jed_saka.m, converts a Saka YMDF date to a JED.
• ymdf_to_jed_soor_san.m, converts a Soor San YMDF date to a JED.
• ymdf_to_jed_syrian.m, converts a Syrian YMDF date to a JED.
• ymdf_to_jed_zoroastrian.m, converts a Zoroastrian YMDF date to a JED.
• ymdf_to_s_common.m, writes a Common YMDF date into a string.
• ymdf_to_s_english.m, writes an English YMDF date into a string.
• ymdf_to_s_gregorian.m, writes a Gregorian YMDF date into a string.
• ymdf_to_s_hebrew.m, writes a Hebrew YMDF date into a string.
• ymdf_to_s_islamic.m, writes an Islamic YMDF date into a string.
• ymdf_to_s_julian.m, writes a Julian YMDF date into a string.
• ymdf_to_s_numeric.m, writes a YMDF date into a string.
• ymdf_to_s_republican.m, writes a Republican YMDF date into a string.
• ymdf_to_s_roman.m, writes a Roman YMDF date into a string.
• ymdf_to_week_common.m, returns the week number of a Common YMDF date.
• ymdf_to_weekday_common.m, returns the weekday of a Common YMDF date.
• ymdf_to_weekday_english.m, returns the weekday of an English YMDF date.
• ymdf_to_weekday_english2.m, returns the weekday of an English YMDF date.
• ymdf_to_weekday_gregorian.m, returns the weekday of a Gregorian YMDF date.
• ymdf_to_weekday_gregorian2.m, returns the weekday of a Gregorian YMDF date.
• ymdf_to_weekday_gregorian3.m, returns the weekday of a Gregorian YMDF date.
• ymdf_to_weekday_gregorian4.m, returns the weekday of a Gregorian YMDF date.
• ymdf_to_weekday_gregorian5.m, returns the weekday of a Gregorian YMDF date.
• ymdf_to_weekday_hebrew.m, returns the weekday of a Hebrew YMDF date.
• ymdf_to_weekday_islamic_a.m, returns the weekday of an Islamic A YMDF date.
• ymdf_to_weekday_julian.m, returns the weekday of a Julian YMDF date.
• ymdf_to_weekday_julian2.m, returns the weekday of a Julian YMDF date.
• ymdf_to_weekday_julian3.m, returns the weekday of a Julian YMDF date.
• ymdf_to_weekday_republican.m, returns the weekday of a Republican YMDF date.
• ymdf_to_yjf_common.m, converts from YMDF to YJF form in the Common calendar.
• ymdf_to_yjf_english.m, converts from YMDF to YJF form in the English calendar.
• ymdf_to_yjf_gregorian.m, converts from YMDF to YJF form in the Gregorian calendar.
• ymdf_to_yjf_hebrew.m, converts from YMDF to YJF form in the Hebrew calendar.
• ymdf_to_yjf_islamic.m, converts from YMDF to YJF form in the Islamic calendar.
• ymdf_to_yjf_julian.m, converts from YMDF to YJF form in the Julian calendar.
• ymdf_to_yjf_republican.m, converts from YMDF to YJF form in the Republican calendar.
• ymdf_to_yjf_roman.m, converts from YMDF to YJF form in the Roman calendar.
• ymdf_uniform_common.m, picks a random Common YMDF date between two given dates.
• ymdf_uniform_english.m, picks a random English YMDF date between two given dates.
• ymdhms_check_common.m, checks a Common YMDHMS date.
• ymdhms_compare.m, compares two Common YMDHMS dates.
• ymdhms_swap.m, swaps two YMDHMS dates.
• ymdhms_to_decimal.m, converts a YMDHMS date to a Decimal YF date.
• ymdhms_to_jed_common.m, converts a Common YMDHMS date to a JED.
• ymdhms_to_s_common.m, converts a Common YMDHMS date to a string.
• ymdhms_to_yjf_common.m, converts a Common YMDHMS date to a YJF date.
• ymdf_to_yjf_english.m, converts an English YMDF date to YJF format.
• ymdf_to_yjf_gregorian.m, converts a Gregorian YMDF date to YJF format.
• ymdf_uniform_common.m, random Common YMDF date between two given dates.
• ymdhms_to_ymdf_common.m, converts a Common YMDHMS date to a YMDF date.
• ymdhms_uniform_common.m, random Common YMDHMS date between two given dates.