| /* $selId: french.c,v 2.0 1995/10/24 01:13:06 lees Exp $ | |
| * Copyright 1993-1995, Scott E. Lee, all rights reserved. | |
| * Permission granted to use, copy, modify, distribute and sell so long as | |
| * the above copyright and this permission statement are retained in all | |
| * copies. THERE IS NO WARRANTY - USE AT YOUR OWN RISK. | |
| */ | |
| /************************************************************************** | |
| * | |
| * These are the externally visible components of this file: | |
| * | |
| * void | |
| * SdnToFrench( | |
| * long int sdn, | |
| * int *pYear, | |
| * int *pMonth, | |
| * int *pDay); | |
| * | |
| * Convert a SDN to a French republican calendar date. If the input SDN is | |
| * before the first day of year 1 or after the last day of year 14, the | |
| * three output values will all be set to zero, otherwise *pYear will be in | |
| * the range 1 to 14 inclusive; *pMonth will be in the range 1 to 13 | |
| * inclusive; *pDay will be in the range 1 to 30 inclusive. If *pMonth is | |
| * 13, the SDN represents one of the holidays at the end of the year and | |
| * *pDay will be in the range 1 to 6 inclusive. | |
| * | |
| * long int | |
| * FrenchToSdn( | |
| * int year, | |
| * int month, | |
| * int day); | |
| * | |
| * Convert a French republican calendar date to a SDN. Zero is returned | |
| * when the input date is detected as invalid or out of the supported | |
| * range. The return value will be > 0 for all valid, supported dates, but | |
| * there are some invalid dates that will return a positive value. To | |
| * verify that a date is valid, convert it to SDN and then back and compare | |
| * with the original. | |
| * | |
| * char *FrenchMonthName[14]; | |
| * | |
| * Convert a French republican month number (1 to 13) to the name of the | |
| * French republican month (null terminated). An index of 13 (for the | |
| * "extra" days at the end of the year) will return the string "Extra". An | |
| * index of zero will return a zero length string. | |
| * | |
| * VALID RANGE | |
| * | |
| * These routines only convert dates in years 1 through 14 (Gregorian | |
| * dates 22 September 1792 through 22 September 1806). This more than | |
| * covers the period when the calendar was in use. | |
| * | |
| * I would support a wider range of dates, but I have not been able to | |
| * find an authoritative definition of when leap years were to have | |
| * occurred. There are suggestions that it was to skip a leap year ever | |
| * 100 years like the Gregorian calendar. | |
| * | |
| * CALENDAR OVERVIEW | |
| * | |
| * The French republican calendar was adopted in October 1793 during | |
| * the French Revolution and was abandoned in January 1806. The intent | |
| * was to create a new calendar system that was based on scientific | |
| * principals, not religious traditions. | |
| * | |
| * The year is divided into 12 months of 30 days each. The remaining 5 | |
| * to 6 days in the year are grouped at the end and are holidays. Each | |
| * month is divided into three decades (instead of weeks) of 10 days | |
| * each. | |
| * | |
| * The epoch (first day of the first year) is 22 September 1792 in the | |
| * Gregorian calendar. Leap years are every fourth year (year 3, 7, | |
| * 11, etc.) | |
| * | |
| * TESTING | |
| * | |
| * This algorithm has been tested from the year 1 to 14. The source | |
| * code of the verification program is included in this package. | |
| * | |
| * REFERENCES | |
| * | |
| * I have found no detailed, authoritative reference on this calendar. | |
| * The algorithms are based on a preponderance of less authoritative | |
| * sources. | |
| * | |
| **************************************************************************/ | |
| void SdnToFrench( | |
| zend_long sdn, | |
| int *pYear, | |
| int *pMonth, | |
| int *pDay) | |
| { | |
| zend_long temp; | |
| int dayOfYear; | |
| if (sdn < FIRST_VALID || sdn > LAST_VALID) { | |
| *pYear = 0; | |
| *pMonth = 0; | |
| *pDay = 0; | |
| return; | |
| } | |
| temp = (sdn - FRENCH_SDN_OFFSET) * 4 - 1; | |
| *pYear = temp / DAYS_PER_4_YEARS; | |
| dayOfYear = (temp % DAYS_PER_4_YEARS) / 4; | |
| *pMonth = dayOfYear / DAYS_PER_MONTH + 1; | |
| *pDay = dayOfYear % DAYS_PER_MONTH + 1; | |
| } | |
| zend_long FrenchToSdn( | |
| int year, | |
| int month, | |
| int day) | |
| { | |
| /* check for invalid dates */ | |
| if (year < 1 || year > 14 || | |
| month < 1 || month > 13 || | |
| day < 1 || day > 30) { | |
| return (0); | |
| } | |
| return ((year * DAYS_PER_4_YEARS) / 4 | |
| + (month - 1) * DAYS_PER_MONTH | |
| + day | |
| + FRENCH_SDN_OFFSET); | |
| } | |
| const char * const FrenchMonthName[14] = | |
| { | |
| "", | |
| "Vendemiaire", | |
| "Brumaire", | |
| "Frimaire", | |
| "Nivose", | |
| "Pluviose", | |
| "Ventose", | |
| "Germinal", | |
| "Floreal", | |
| "Prairial", | |
| "Messidor", | |
| "Thermidor", | |
| "Fructidor", | |
| "Extra" | |
| }; | |