/******************************************************************** This work is licensed under the Creative Commons NonCommercial- ShareAlike License. To view a copy of this license, visit http://creativecommons.org/licenses/nc-sa/1.0 And sticking with the theme, I'm making an additional request: if you do end up using the code, do a good deed in return - donate some money to your favorite charity, help out at a food kitchen, etc. The software is provided "as is" and "with all faults." The author makes no representations or warranties of any kind concerning the quality, accuracy or suitability of the software, either express or implied. ********************************************************************/ /******************************************************************** zcalendar.js Javascript methods to perform calculations based on the Shenshai/Fasli calendar. Generally speaking, with regard to function names, "Roj" indicates a Zoroastrian Calendar convertRojToDate(roj, mah, yzYear) converts roj/mah/yzYear to gregorian date convertRojToDateInYear(roj, mah, gregorianYear) Determines date that roj and mah occurs in gregorian year. convertDateToRoj(aDate) - converts a gregorian date to roj/mah/yzYear. returns a ZCalendar.CalendarDate. convertDateToRojInYear(aDate, year) - converts a gregorian date to roj/mah/yzYear and determines when the roj occurs in the given gregorian year. returns a ZCalendar.CalendarDate mapRojToYear(aDate,aYear) - Determines roj date for a given year based on a given date. getNavrozeDate(aYear) - Calculate Navroze (New Year) for a given year. getPrecedingNavrozeDate(date) - Calculate preceding Navroze (New Year) for a given date. getRojNamesForMonth(aDate) - Returns a DayMonthPair array of the names of the roj/mah for the days in the month of the given date. buildCalendar(aDate) - builds a calendar month in HTML showing roj/mah names. Dependencies - prototype.js ********************************************************************/ // check dependencies if(typeof Prototype=='undefined') throw("ZCalendar requires the Prototype JavaScript framework >= 1.3"); Array.prototype.indexOf = function(value) { for (var i=0; i0 && calType!=null) calType = cType; if (calType==this.FASLI) { return ZCalendar.Fasli; } else if (calType==this.KADMI) { return ZCalendar.Kadmi; } else { // use Shenshai calendar by default return ZCalendar.Shenshai; } }, /** * Gets a calendar implementation and renders an HTML calendar. * @param aDate - Gregorian date specifying month/year to render * @return an HTML string of the calendar for the month */ buildCalendar: function(aDate) { // delegate to specific calendar implementation return this.getCalendar().buildCalendar(aDate); } }; /* * A utility object to hold the roj/mah/year info */ ZCalendar.CalendarDate = Class.create(); ZCalendar.CalendarDate.prototype = { // constructor initialize: function(rojName, mahName, zYear, date) { this.roj = rojName; this.mah= mahName || ""; this.yzYear= zYear || ""; this.gregorianDate = date; }, equals: function(cal) { if (cal == null) return false; else if ( ((this.roj==null && cal.roj==null) || this.roj == cal.roj) && ((this.mah==null && cal.mah==null) || this.mah == cal.mah) && //((this.yzYear==null && cal.yzYear==null) || this.yzYear == cal.yzYear) && ((this.gregorianDate==null && cal.gregorianDate==null) || this.gregorianDate.getTime() == cal.gregorianDate.getTime()) ) { return true; } return false; }, toString: function() { var msg = "" + this.roj + " roj"; if (this.mah != null && this.mah != "") { msg += ", " + this.mah + " mah" ; } //if (this.yzYear != null && this.yzYear != "") { // msg += ", " + this.yzYear + " Y.Z." ; //} return msg; }, toFullString: function() { var msg = this.toString(); if (this.gregorianDate != null && this.gregorianDate != "") { msg += ", occurs on " + this.gregorianDate.format("month dd, yyyy"); } return msg; }, debug: function() { s = "CalendarDate: roj="+this.roj+" mah="+this.mah+" yzYear="+this.yzYear+" gregorianDate=" + this.gregorianDate; return s; } }; /******************************************************************** Abstract Base Calendar ********************************************************************/ // try a little oo goodness here... abstract base class containing // methods common to calendar subclasses ZCalendar.AbstractBaseCalendar = { EPOCH_YEAR: 1129, EPOCH_DATE: new Date(1129, 2, 21), EQUINOX_DATE: new Date(new Date().getFullYear(), 2, 21), YZ_EPOCH_DATE: new Date(632, 6, 16), MAH: new Array( "Fravardin","Ardibehesht","Khordad","Tir","Amardad","Shehrevar", "Meher","Avan","Adar","Dae","Bahman","Aspandard"), ROJ: new Array( "Hormazd", "Bahman", "Ardibehesht", "Shehrevar", "Aspandard", "Khordad", "Amardad","Dae-Pa-Adar","Adar","Avan", "Khorshed","Mohor","Tir", "Gosh","Dae-Pa-Meher", "Meher","Srosh","Rashne","Fravardin","Behram", "Ram","Govad","Dae-Pa-Din","Din","Ashishvangh", "Ashtad","Asman","Zamyad","Mareshpand","Aneran"), GATHAS: new Array("Ahunavaiti", "Ushtavaiti","Spentamainyu","Vohuxshathra","Vahishtoishti"), calendarType: "", /* * Returns a formatted string showing today's * Zoroastrian date info (roj,mah,year) */ getZDateForToday: function() { // get the zdate using today's gregorian date calDate = this.convertDateToRoj(new Date()); // build the result message msg = "Today is " + calDate.toString(); msg += " (" + this.calendarType + ")"; return msg; }, /** * Given a gregorian date, find when the corresponding roj occurs in the given year. * @param aDate - a date to calculate the roj from; * @param aYear - the year in which to calculate when the roj occurs * @returns - a Date object representing the roj on which the date * falls in the gregorian calendar * @deprecated - use convertDateToRojInYear */ mapRojToYear: function(aDate, aYear) { throw("AbstractBaseCalendar.mapRojToYear() - implement in subclass"); }, /** * Convert a Zoroastrian Date to Gregorian Date. * @param roj - the roj name * @param mah - the mah name * @param yzYear - the Yazdegard era year * @return - a Date object representing when in the Gregorian calendar the roj occurs */ convertRojToDate: function(roj, mah, yzYear) { throw("AbstractBaseCalendar.convertRojToDate() - unimplemented"); }, /** * Determines the date for a given roj and mah in a given year * @param roj - the roj name * @param mah- the mah name * @param aYear - Gregorian year in which to find when the roj/mah occurs (e.g., 2002) * @returns - a Date object representing the gregorian date on which the roj/mah * occurs in the gregorian calendar */ convertRojToDateInYear: function(roj, mah, year) { var currentDate = new Date(); var months = 0; var days = 0; var diff; var isLeapYear = new Date(year, 0, 1).isLeapYear(); // figure out the number of days // determine the difference in days between the date given and // the prior navroze var gathaIndex = this.GATHAS.indexOf(roj); if (gathaIndex > -1) { diff = gathaIndex + 360; } else { var rojIndex = this.ROJ.indexOf(roj); var mahIndex = this.MAH.indexOf(mah); diff = Number(mahIndex * 30) + Number(rojIndex); //alert("rx=" +rojIndex+ " mx=" +mahIndex+ " diff=" + diff); } //alert(" diff=" + diff); var resultDate, navroze; var navrozeYear = year-1; // we need to determine if we should add diff to given year's // navroze or previous year's navroze. // if the days to add (diff) to the navroze puts us in the // wrong year, recalculate using the previous year's // navroze. This is basically the same calc, only we start // with navroze for previous year, and if years don't match, // recalculate for current year. do { navroze = this.getNavrozeDate(navrozeYear++); resultDate = navroze.clone(); resultDate.addDay(diff); } while (resultDate.getFullYear() < year) return resultDate; }, /** * Returns a CalendarDate containing Zoroastrian Date info (roj/mah/YZ year) * corresponding to the given gregorian date. * If the day has no mah (e.g., gathas), then mah will be set to null. * @param aDate - the gregorian date to convert to zoroastring date * @return - a CalendarDate containing Zoroastrian Date info (roj/mah/YZ year) */ convertDateToRoj: function(aDate) { // the roj/month name is determined by difference in days // between the date provided and the newyear (navroze), // then finding the corresponding value in the ROJ/MAH // arrays. For example, if the given date was 65 days past // navroze, then that falls on the fifth day of the second month. // The exception to the rule is if the difference in days is // greater than 360. In this case, since 12 months * 30 days // only adds up to 360, we need to look up the day in the // GATHAS array. var months; var days; var diff; // the CalendarDate will hold the roj/mah name var calDate = new ZCalendar.CalendarDate(); // first figure out when navroze is on the year var navroze = this.getPrecedingNavrozeDate(aDate); // determine the difference in days between the date given and // the prior navroze diffInDays = Date.daysDiff(aDate, navroze); // if the difference in days greater than 360, then lookup the name // in the GATHAS array if (diffInDays >= 360) { days = diffInDays%30; calDate.roj = this.GATHAS[days]; //calDate.month = ""; } // otherwise figure out how many months + how many days // this difference corresponds to, and retrieve the corresponding // names from the ROJ/MAH array else { months = Math.floor(diffInDays/30); days = diffInDays%30; calDate.roj = this.ROJ[days]; calDate.mah = this.MAH[months]; } var zyear = this.computeYZYear(aDate); calDate.yzYear = zyear; return calDate; }, /** * Returns a CalendarDate containing Zoroastrian date info (roj/mah/YZ year) * corresponding to the given date in the given year. * Implemented by computing the roj/mah for the given date, then computing * when in the given year that roj/mah occurs. * @param aDate - the gregorian date to convert to zoroastring date * @param year - the gregorian year in which to compute when the roj/mah * for the given date occurs * @return - a CalendarDate containing month name and roj name and * the gregorian date on which the roj/mah occurs in the specified year */ convertDateToRojInYear: function(aDate, year) { // get the roj name of the roj var zcalDate = this.convertDateToRoj(aDate); // either approach should work... //var rojDate = calendar.mapRojToYear(inputDate, inputYear); zcalDate.gregorianDate = this.convertRojToDateInYear(zcalDate.roj, zcalDate.mah, year); return zcalDate; }, /** * Computes the Yazdegard year for a Gregorian date. * @param aDate - a gregorian date * @returns - the Yazdegard year for the gregorian date in "yyyy" format */ computeYZYear: function(aDate) { return Date.yearsDiff(this.YZ_EPOCH_DATE, aDate); }, /** * Calculate Navroze (New Year) for a given year. * @param aYear - the year ('yyyy' format) for which to calculate navroze * @return - a Date object representing Navroze */ getNavrozeDate: function(aYear) { throw("AbstractBaseCalendar.getNavrozeDate() - implement in subclass"); }, /** * Calculate the Navroze (New Year) date occuring on or before the given * date * @param aDate - the date to find preceding Navroze for * @return - a Date object representing the preceding Navroze */ getPrecedingNavrozeDate: function(aDate) { var navroze = this.getNavrozeDate(aDate.getFullYear()); if (aDate < navroze) { navroze = this.getNavrozeDate(aDate.getFullYear() - 1); } return navroze; }, /** * Returns a CalendarDate array of the names of the roj/mah for * the days in the month of the given date. * * This function is a helper function to buildCalendar. * @param aDate - the Date to retrieve the roj/mah names for * @return - an array of DayMonthPair objects populated with the * names of roj/mah for all the days in the month */ getRojNamesForMonth: function(aDate) { throw("AbstractBaseCalendar.getRojNamesForMonth() - implement in subclass"); }, /** * Returns a string displaying a calendar month in HTML. * The calendar month shows the gregorian calendar date along * with the Zoroastrian calendar roj/mah name. * @param aDate - the date to build the calendar month for * @return - an html string of the month. */ buildCalendar: function(aDate) { var dayCounter = 1; var dayOfWeekCounter = 0; var s; var isCalendarForCurrentMonth = false; var currentDate = new Date(); var currentDayInMonth = currentDate.getDate(); var calDate = new Date(aDate.getFullYear(), aDate.getMonth(), 1); // determine what day of the week the first of the month falls on var firstDayOfMonth = calDate.getDay(); // get the number of days in the month var daysInMonth = aDate.getDaysInMonth(); // figure out if this is calendar is for the current month if ( (currentDate.getMonth() == aDate.getMonth()) && currentDate.getFullYear() == aDate.getFullYear()) { isCalendarForCurrentMonth = true; } // html to use for a blank day var blankDay = " "; // get the roj/mah names corressponding to the calendar month var rojArray = this.getRojNamesForMonth(calDate); //alert("rojArray="+rojArray + " length=" + rojArray.length); // open the table and append the header row of day names s = "

" + calDate.format("month yyyy") + "

"; s += ""; s += ""; // first build the blank days (e.g. if the first falls on a Fri) for (i = 0; i < firstDayOfMonth; i++) { s += blankDay; dayOfWeekCounter++; } // next build the calendar for the number of days in the month for (i = 1; i <= daysInMonth; i++) { // build the cell for the day // if the cell is for today (current date)... if (isCalendarForCurrentMonth && i == currentDayInMonth) { s += ""; dayOfWeekCounter++; // if this is the 7th day, add a row break if (dayOfWeekCounter % 7 == 0) { s += ""; } } // next build the blank days at the end of the month (e.g. if // the month ends on a wed, we need to add a few blank days till // the end of the week. for (i = dayOfWeekCounter % 7; i < 7; i++) { s += blankDay; } // close the table s += "
Sun Mon Tue Wed Thu Fri Sat
"; } else { s +=""; } s += "" + i + "

" + rojArray[i-1].roj + "
" + (rojArray[i-1].mah == ""?"":"("+ rojArray[i-1].mah + ")") + "
" // alert(s); return s; } } /******************************************************************** Shenshai Calendar ********************************************************************/ // use prototype.js for oo behavior ZCalendar.Shenshai = new Object(); // Shenshai calendar extends AbstractBaseCalendar Object.extend(ZCalendar.Shenshai , ZCalendar.AbstractBaseCalendar); // Shenshai calendar implementation Object.extend(ZCalendar.Shenshai , { MAH: new Array( "Fravardin","Ardibehesht","Khordad","Tir","Amardad","Shehrevar", "Meher","Avan","Adar","Dae","Bahman","Aspandard"), ROJ: new Array( "Hormazd", "Bahman", "Ardibehesht", "Shehrevar", "Aspandard", "Khordad", "Amardad","Dae-Pa-Adar","Adar","Avan", "Khorshed","Mohor","Tir", "Gosh","Dae-Pa-Meher", "Meher","Srosh","Rashne","Fravardin","Behram", "Ram","Govad","Dae-Pa-Din","Din","Ashishvangh", "Ashtad","Asman","Zamyad","Mareshpand","Aneran"), GATHAS: new Array("Ahunavaiti", "Ushtavaiti","Spentamainyu","Vohuxshathra","Vahishtoishti"), calendarType: "Shenshai", /* * @see ZCalendar.AbstractBaseCalendar#getNavrozeDate */ getNavrozeDate: function(aYear) { // Navroze is determined by calculating the difference in days // between an "epoch" date and the equinox in the given year. // The epoch date is Mar-21-1129, the last navroze when the // additional 30 days was intercalated to account for ~1/4 day // difference between the solar calendar and the Shenshai calendar. var daysInYearUntilEquinox = 69; // get the equinox for the current year var currentEquinox = this.EQUINOX_DATE.clone(); currentEquinox.setFullYear(aYear); // Determine the difference in years between the epoch date and the // equinox on the current year var yearsDiff = Date.yearsDiff(currentEquinox, this.EPOCH_DATE) + 0; var currentNavroze = this.EPOCH_DATE.clone() // add the difference in years * 365 to the epochDate if (yearsDiff > daysInYearUntilEquinox) { currentNavroze.addDay((yearsDiff+1) * 365); } else { currentNavroze.addDay(yearsDiff * 365); } return currentNavroze; }, /* * @see ZCalendar.AbstractBaseCalendar#mapRojToYear */ mapRojToYear: function(aDate, aYear) { // to figure out the roj, find the difference in years // between the date provided and the year provided var rojDate = aDate.clone(); var calcDate = new Date(aYear, aDate.getMonth(), aDate.getDate()); var yearsDiff = Date.yearsDiff(calcDate, aDate); // the roj is the date provided + (the difference in years * 365) rojDate.addDay(yearsDiff * 365); return rojDate; }, /* * @see ZCalendar.AbstractBaseCalendar#getRojNamesForMonth */ getRojNamesForMonth: function(aDate) { // Similar to calculating the roj name, we need to figure out the // difference in days between the first day of the given month and // the prior navroze. Then map the difference to the ROJ/MAH array, // and populate the resulting array with roj/mah values for the // number of days in the month of the given date. var months = 0; var days = 0; var diffInDays = 0; var dayOffset = 0; // calculate the number of days in the month var daysInMonth = aDate.getDaysInMonth(); // create a new array to hold results var result = new Array(daysInMonth); // determine the prior navroze for the given year var navroze = this.getPrecedingNavrozeDate(aDate); //alert("navroz=" + navroze); // determine the difference in days between prior navroze and // the given date daysFromNavroze = Date.daysDiff(aDate, navroze); // loop through the days in the month, getting the roj/mah name for // each corresponding day. for (i=0; i < daysInMonth; i++) { diffInDays = daysFromNavroze + dayOffset; days = diffInDays % 30; // if the difference in days is > 360, these are gathas which // have no corresponding month, so pull values from GATHAS array // and leave month blank if ((diffInDays >= 360) && (diffInDays < 365)) { result[i] = new ZCalendar.CalendarDate(this.GATHAS[days]); } // if the difference in days is 365, then we need to reset the // days arg back to 0 to start at the beginning of the month else if (diffInDays == 365) { days = 0; daysFromNavroze = 0; dayOffset = 0; result[i] = new ZCalendar.CalendarDate(this.ROJ[days], this.MAH[0], ""); } // otherwise get the roj/mah name from the ROJ/MAH arrays based // on the difference in days number. else { months = Math.floor((diffInDays)/30); // alert(months); result[i] = new ZCalendar.CalendarDate(this.ROJ[days], this.MAH[months], ""); } dayOffset++; } // uncomment for debugging //alert("" + this.ROJ[days] + " " + this.MAH[months]); //var s = ""; //for (i=0; i 360, these are gathas which // have no corresponding month, so pull values from GATHAS array // and leave month blank // for fasli calendar, if it's a leap year, tack on the extra day if ((!aDate.isLeapYear() && (diffInDays >= 360) && (diffInDays < 365)) || (aDate.isLeapYear() && (diffInDays >= 360) && (diffInDays < 366)) ) { result[i] = new ZCalendar.CalendarDate(this.GATHAS[days],"", ""); } else if (aDate.isLeapYear() && (diffInDays >= 360) && (diffInDays < 366)) { result[i] = new ZCalendar.CalendarDate(this.GATHAS[days],"", ""); } // if the difference in days is 365 (or 366 for leap years), then we need to reset the // days arg back to 0 to start at the beginning of the month else if ((!aDate.isLeapYear() && diffInDays == 365) || (aDate.isLeapYear() && diffInDays == 366)) { days = 0; daysFromNavroze = 0; dayOffset = 0; result[i] = new ZCalendar.CalendarDate(this.ROJ[days], this.MAH[0], ""); } // otherwise get the roj/mah name from the ROJ/MAH arrays based // on the difference in days number. else { months = Math.floor((diffInDays)/30); // alert(months); result[i] = new ZCalendar.CalendarDate(this.ROJ[days], this.MAH[months], ""); } dayOffset++; } // uncomment for debugging //alert("" + this.ROJ[days] + " " + this.MAH[months]); //var s = ""; //for (i=0; i