dc21d42001-05-05Mirar (Pontus Hagland) //! //! module Calendar
ac638c2001-07-17Martin Nilsson //! submodule Islamic
dc21d42001-05-05Mirar (Pontus Hagland) //!
78fd532000-07-12Mirar (Pontus Hagland) //! This is the islamic calendar. Due to some sources, //! they decide the first day of the new months on a //! month-to-month basis (sightings of the new moon),
dc21d42001-05-05Mirar (Pontus Hagland) //! so it's probably not <i>that</i> accurate. If
78fd532000-07-12Mirar (Pontus Hagland) //! someone can confirm (or deny) accuracy better than that, //! please contact me so I can change this statement. //! //! It's vaugely based on rules presented in algorithms by //! Dershowitz, Reingold and Clamen, 'Calendrical Calculations'. //! It is the same that's used in Emacs calendar mode. //!
dc21d42001-05-05Mirar (Pontus Hagland) //! known bugs:
78fd532000-07-12Mirar (Pontus Hagland) //! I have currently no idea how the arabic countries
dc21d42001-05-05Mirar (Pontus Hagland) //! count the week. Follow the same rules as ISO
78fd532000-07-12Mirar (Pontus Hagland) //! for now... The time is also suspicious; the *day* //! really starts at sunrise (sunset?) and not midnight,
dc21d42001-05-05Mirar (Pontus Hagland) //! the hours of the day is not correct. Also don't know
78fd532000-07-12Mirar (Pontus Hagland) //! what to call years before 1 - go for "BH"; positive //! years are "AH", anno Hegirac. //!
a580e12000-09-27Fredrik Hübinette (Hubbe) #pike __REAL_VERSION__
a20af62000-09-26Fredrik Hübinette (Hubbe) 
78fd532000-07-12Mirar (Pontus Hagland) import "."; inherit YMD:YMD;
2099482001-01-11Mirar (Pontus Hagland) #include "constants.h"
78fd532000-07-12Mirar (Pontus Hagland) string calendar_name() { return "Islamic"; } private static mixed __initstuff=lambda() { f_week_day_shortname_from_number="islamic_week_day_shortname_from_number"; f_week_day_name_from_number="islamic_week_day_name_from_number"; f_year_name_from_number="islamic_year_name_from_number"; f_month_day_name_from_number="month_day_name_from_number"; f_month_name_from_number="islamic_month_name_from_number"; f_month_shortname_from_number="islamic_month_shortname_from_number"; f_month_number_from_name="islamic_month_number_from_name"; f_week_day_number_from_name="gregorian_week_day_number_from_name"; f_week_name_from_number="week_name_from_number"; }(); int year_leap_year(int y) { return (14+11*y)%30<11; } int julian_day_from_year(int y) { return (y-1)*354 + (11*y+3)/30 + 1948440; } array(int) year_from_julian_day(int jd) { // [y,yjd] jd-=1948440; int tr=jd/10631; int td=jd-tr*10631; int y=(14+td*30)/10631+tr*30+1; return ({y, (y-1)*354 + (11*y+3)/30 + 1948440}); } static array(int) year_month_from_month(int y,int m) { // [y,m,ndays,myd] y+=(m-1)/12; m=1+(m-1)%12; switch (m) { case 1: return ({y,m,30, 1}); case 2: return ({y,m,29, 31}); case 3: return ({y,m,30, 60}); case 4: return ({y,m,29, 90}); case 5: return ({y,m,30,119}); case 6: return ({y,m,29,149}); case 7: return ({y,m,30,178}); case 8: return ({y,m,29,208}); case 9: return ({y,m,30,237}); case 10: return ({y,m,29,267}); case 11: return ({y,m,30,296}); case 12: return ({y,m,29+year_leap_year(y),326}); } error("month out of range\n"); } static array(int) month_from_yday(int y,int yd) { // [month,day-of-month,ndays,month-year-day] int l=year_leap_year(y); switch (yd) { case 1.. 30: return ({ 1,yd, 30, 1}); case 31.. 59: return ({ 2,yd- 30,29, 31}); case 60.. 89: return ({ 3,yd- 59,30, 60}); case 90..118: return ({ 4,yd- 89,29, 90}); case 119..148: return ({ 5,yd-118,30,119}); case 149..177: return ({ 6,yd-148,29,149}); case 178..207: return ({ 7,yd-177,30,178}); case 208..236: return ({ 8,yd-207,29,208}); case 237..266: return ({ 9,yd-236,30,237}); case 267..295: return ({10,yd-266,29,267}); case 296..325: return ({11,yd-295,30,296}); case 326..: return ({12,yd-326,29+year_leap_year(y),326}); } error("yday out of range\n"); } static array(int) week_from_julian_day(int jd) { // [year,week,day-of-week,ndays,week-julian-day] [int y,int yjd]=year_from_julian_day(jd); int yday=jd-yjd+1; int k=4+(yjd-4)%7; int w=(yday+k)/7; int wjd=jd-(jd+1)%7; // fixme: week number return ({y,w,1+(yjd+yday)%7,7,wjd}); } static array(int) week_from_week(int y,int w) { // [year,week,1 (wd),ndays,week-julian-day] int yjd=julian_day_from_year(y); int wjd=-5+yjd-(yjd+3)%7; // fixme: week number return ({y,w,1,7,wjd+w*7}); } static int compat_week_day(int n) { return n%7; } static int year_remaining_days(int y,int yday) { return 354+year_leap_year(y)-yday; } class cYear { inherit YMD::cYear; int number_of_days() { switch (n) { case 0: return 0; case 1: return 354+leap_year(); default: return julian_day_from_year(y+n)-yjd; } } int number_of_months() { return 12*n; } int number_of_weeks() { if (!n) return 1; // if (n==1) return 51; return Week("julian",jd) ->range(Week("julian",julian_day_from_year(y+n)-1)) ->number_of_weeks(); } TimeRange place(TimeRange what,void|int force) { if (what->is_day) { int yd=what->yd; if (yd==355 && !year_leap_year(y)) if (!force) return 0; // can't place else return Day("julian_r",julian_day_from_year(y+1),rules); return Day("ymd_yd",rules,y,yjd,yjd+yd-1,yd,what->n); } return ::place(what,force); } } class cDay { inherit YMD::cDay; int number_of_months() { if (n<=1) return 1; if (m==CALUNKNOWN) make_month(); [int zy,int zyjd]=year_from_julian_day(jd+n-1); [int zm,int zmd,int znd,int zmyd]=month_from_yday(zy,jd+n-zyjd); return zm-m+1+(zy-y)*12; } } class cMonth { inherit YMD::cMonth; static int months_to_month(int y2,int m2) { return (y2-y)*12+(m2-m); } } class cWeek { inherit YMD::cWeek; static int weeks_to_week(int y2,int w2) { [int y3,int w3,int wd2,int nd2,int jd2]=week_from_week(y2,w2); return (jd2-jd)/7; } int number_of_days() { return 7*n; } }