/* kdate.js - Kaluach Javascript Hebrew date routines
 *   Version 0.03 (beta release)
 * Copyright (C) 5760 (2000 CE), by Abu Mami and Yisrael Hersch.
 *   All Rights Reserved.
 *   All copyright notices in this script must be left intact.
 * Based on the formula by Gauss
 * Terms of use:
 *   - Permission will be granted to use this script on personal
 *     web pages. All that's required is that you please ask.
 *     (Of course if you want to send a few dollars, that's OK too :-)
 *   - Use on commercial web sites requires a $50 payment.
 * website: http://www.kaluach.net
 * email: abu-mami@kaluach.net
 */

function makeArray() {
	this[0] = makeArray.arguments.length;
	for (i = 0; i < makeArray.arguments.length; i = i + 1)
		this[i+1] = makeArray.arguments[i];
}

var hebMonth = new makeArray(
	'Nisan', 'Iyyar', 'Sivan', 'Tammuz', 'Av', 'Elul',
	'Tishrei', 'Cheshvan', 'Kislev', 'Tevet', 'Shevat',
	'Adar', 'Adar I', 'Adar II');

var civMonth = new makeArray(
	'January', 'February', 'March', 'April', 'May', 'June',
	'July', 'August', 'September', 'October', 'November', 'December');

var weekDay = new makeArray(
	'Sun', 'Mon', 'Tues', 'Wed', 'Thur', 'Fri', 'Shabbat');

function Gauss(year) {
	var a,b,c;
	var m;
	var	Mar;	// "day in March" on which Pesach falls (return value)

	a = Math.floor((12 * year + 17) % 19);
	b = Math.floor(year % 4);
	m = 32.044093161144 + 1.5542417966212 * a +  b / 4.0 - 0.0031777940220923 * year;
	if (m < 0)
		m -= 1;
	Mar = Math.floor(m);
	if (m < 0)
		m++;
	m -= Mar;

	c = Math.floor((Mar + 3 * year + 5 * b + 5) % 7);
	if(c == 0 && a > 11 && m >= 0.89772376543210 )
		Mar++;
	else if(c == 1 && a > 6 && m >= 0.63287037037037)
		Mar += 2;
	else if(c == 2 || c == 4 || c == 6)
		Mar++;

	Mar += Math.floor((year - 3760) / 100) - Math.floor((year - 3760) / 400) - 2;
	return Mar;
}

function leap(y) {
	return ((y % 400 == 0) || (y % 100 != 0 && y % 4 == 0));
}

function civMonthLength(month, year) {
	if(month == 2)
		return 28 + leap(year);
	else if(month == 4 || month == 6 || month == 9 || month == 11)
	   return 30;
	else
		return 31;
}

function civ2heb(day, month, year) {
	var d = day;
	var	m = month;
	var y = year;
	var hy;
	var pesach;
	var anchor;
	var adarType;

	m -= 2;
	if (m <= 0) { // Jan or Feb
		m += 12;
		y -= 1;
	}

	d += Math.floor(7 * m / 12 + 30 * (m - 1)); // day in March
	hy = y + 3760;	// get Hebrew year
	pesach = Gauss(hy);
	if (d <= pesach - 15) { // before 1 Nisan
		anchor = pesach;
		d += 365;
		if(leap(y))
			d++;
		y -= 1;
		hy -= 1;
		pesach = Gauss(hy);
	}
	else
		anchor = Gauss(hy + 1);

	d -= pesach - 15;
	anchor -= pesach - 12;
	y++;
	if(leap(y))
		anchor++;

	for(m = 0; m < 11; m++) {
		var days;
		if(m == 7 && anchor % 30 == 2)
			days = 30; // Cheshvan
		else if(m == 8 && anchor % 30 == 0)
			days = 29; // Kislev
		else
			days = 30 - m % 2;
		if(d <= days)
			break;
		d -= days;
	}

	adarType = 0;			// plain old Adar
	if (m == 11 && anchor >= 30) {
		if (d > 30) {
			adarType = 2;	// Adar 2
			d -= 30;
		}
		else
			adarType = 1;	// Adar 1
	}

	if(m >= 6)		// Tishrei or after?
		hy++;		// then bump up year

	if(m == 11)			// Adar?
		m += adarType;	// adjust for Adars

	return (d + ' ' + m + ' ' + hy);
}


function Easter(Y) {
	// based on the algorithm of Oudin
    var C = Math.floor(Y / 100);
    var N = Y - 19 * Math.floor(Y / 19);
    var K = Math.floor((C - 17) / 25);
    var I = C - Math.floor(C / 4) - Math.floor((C - K) / 3) + 19 * N + 15;
    I = I - 30*Math.floor((I / 30));
    I = I - Math.floor(I / 28) * (1 - Math.floor(I / 28) * Math.floor(29 / (I + 1)) * Math.floor((21 - N) / 11));
    var J = Y + Math.floor(Y / 4) + I + 2 - C + Math.floor(C / 4);
    J = J - 7 * Math.floor(J / 7);
    var L = I - J;
    var M = 3 + Math.floor((L + 40) / 44);
    var D = L + 28 - 31 * Math.floor(M / 4);

	var ret = new Object();
	ret[1] = M;
	ret[2] = D;
	return ret;
}

function DOW(day,month,year) {
	var a = Math.floor((14 - month)/12);
	var y = year - a;
	var m = month + 12*a - 2;
	var d = (day + y + Math.floor(y/4) - Math.floor(y/100) +
			Math.floor(y/400) + Math.floor((31*m)/12)) % 7;
	return d + 1;
}

function NthDOW(nth,weekday,month,year) {
	if (nth > 0)
		return (nth - 1) * 7 + 1 + (7 + weekday - DOW((nth - 1) * 7 + 1, month, year)) % 7;
	var days = civMonthLength(month, year);
	return days - (DOW(days, month, year) - weekday + 7) % 7;
}

function holidays(cday, cmonth, cyear) {
	// American civil holidays and some major religious holiday
	if (cmonth == 1 && cday == 1)
		return "New Year's Day";
	else if (cmonth == 2 && cday == 12)
		return "Lincoln's Birthday";
	else if (cmonth == 2 && cday == 14)
		return "Valentine's Day";
	else if (cmonth == 2 && cday == NthDOW(3, 2, 2, cyear))
		return "President's Day";
	else if (cmonth == 3 && cday == 17)
		return "St. Patrick's Day";
else if (cmonth == 4 && cday == 19)
		return "Holocaust Uprising Remembrance Day";
	else if (cmonth == 3 || cmonth == 4) {
		var e = Easter(cyear);
	    if (cmonth == e[1] && cday == e[2])
			return "Easter";
	}
	
	else if (cmonth == 5 && cday == NthDOW(2, 1, 5, cyear))
		return "Mother's Day";
	else if (cmonth == 5 && cday == NthDOW(3, 7, 5, cyear))
		return "Armed Forces Day";
	else if (cmonth == 5 && cday == NthDOW(0, 2, 5, cyear))
		return "Memorial Day";
	else if (cmonth == 6 && cday == 14)
		return "Flag Day";
	else if (cmonth == 6 && cday == NthDOW(3, 1, 6, cyear))
		return "Father's Day";
	else if (cmonth == 7 && cday == 4)
		return "US Independence Day";
	else if (cmonth == 9 && cday == NthDOW(1, 2, 9, cyear))
		return "Labor Day";
	else if (cmonth == 10 && cday == NthDOW(2, 2, 10, cyear))
		return "Columbus Day";
	else if (cmonth == 10 && cday == 31)
		return "Halloween";
	else if (cmonth == 11 && cday == 11)
		return "Veterans' Day";
	else if (cmonth == 11 && cday == NthDOW(4, 5, 11, cyear))
		return "Thanksgiving Day";
	else if (cmonth == 12 && cday == 25)
		return "Christmas";
	else if (cmonth == 12 && cday == 31)
		return "New Year's Eve";
	return "";
}

function moadim(cday, cmonth, cyear, hday, hmonth, dow) {
	if(hmonth == 6) {
		if(hday == 1 || hday == 2)
			return "Rosh Hashana"
		else if(hday == 3 && dow != 7)
			return "Feast of Gedalia";
		else if(hday == 4 && dow == 1)
			return "Feast of Gedalia";
		else if(hday == 10)
			return "Yom Kippur"
		else if(hday >= 15 && hday <= 22)
			return "Sukkot"
		else if(hday == 23)
			return "Sukkot (d)"
	}
	else if(hmonth == 8) {
		if(hday >= 25)
			return "Chanukkah"
	}
	else if(hmonth == 9) {
		if(hday <= 2) {
			return "Chanukkah"
		}
		else if(hday == 3) {
			// Kislev can be malei or chaser
			if(cday == 1) {
				cday = 29;
				cmonth = 11;
			}
			else if(cday == 2) {
				cday = 30;
				cmonth = 11;
			}
			else
				cday -= 3;
			var hdate = civ2heb(cday, cmonth, cyear);
			hd = eval(hdate.substring(0, hdate.indexOf(' ')));
			if(hd == 29)
				return "Chanukkah"
		}
		else if(hday == 10)
			return "Feast of Tevet"
	}
	else if(hmonth == 10) {
		if(hday==15)
			return "Tu b'Shvat"
	}
	else if(hmonth == 11 || hmonth == 13) {
		if(hday == 11 && dow == 5)
			return "Taanit Esther"
		else if(hday == 13 && dow != 7)
			return "Taanit Esther"
		else if(hday == 14)
			return "Purim"
		else if(hday == 15)
			return "Shushan Purim"
	}
	else if(hmonth == 0) {

		if(hday == 12 && dow == 5)
			return "Taanit Bechorot"
		else if(hday == 14 && dow != 7)
			return "Taanit Bechorot"
		else if(hday >= 15 && hday <= 21)
			return "Pesach"
		else if(hday == 22)
			return "Pesach (d)"
	}
	else if(hmonth == 1) {
		if(hday == 3 && dow == 5)
			return "Yom Ha'Atzmaut"
		else if(hday == 4 && dow == 5)
			return "Yom Ha'Atzmaut"
		else if(hday == 5 && dow != 6 && dow != 7)
			return "Yom Ha'Atzmaut"
		if(hday == 14)
			return "Pesah sheni"
		else if(hday == 18)
			return "Lag B'Omer"
		if(hday == 28)
			return "Yom Yerushalayim"
	}
	else if(hmonth == 2) {
		if(hday == 6)
			return "Shavuot"
		else if(hday == 7)
			return "Shavuot (d)"
	}
	else if(hmonth == 3) {
		if(hday == 17 && dow != 7)
			return "Feast of Tammuz"
		if(hday == 18 && dow == 1)
			return "Feast of Tammuz"
	}
	else if(hmonth == 4) {
		if(hday == 9 && dow != 7)
			return "Tisha B'Av"
		if(hday == 10 && dow == 1)
			return "Tisha B'Av"
		if(hday == 15)
			return "Tu B'Av"
	}

	return "";
}


function WriteHebrewDate(tday, tmonth, tyear){
	var hebDate = civ2heb(tday, tmonth, tyear);
	var hmS = hebDate.substring(hebDate.indexOf(' ')+1, hebDate.length);
	var	hDay = eval(hebDate.substring(0, hebDate.indexOf(' ')));
	var hMonth = eval(hmS.substring(0, hmS.indexOf(' ')));
	var hYear = hmS.substring(hmS.indexOf(' ')+1, hmS.length);
	document.write(hDay + ' ' + hebMonth[hMonth+1] + ' ' + hYear);
}

function WriteJewishHolidays(cDay, cMonth, cYear){
			hebDate = civ2heb(cDay, cMonth, cYear);
			hebDay = eval(hebDate.substring(0, hebDate.indexOf(' ')));
			var hm = hebDate.substring(hebDate.indexOf(' ')+1, hebDate.length);
			var hMonth = eval(hm.substring(0, hm.indexOf(' ')));

moed = moadim(cDay, cMonth, cYear, hebDay, hMonth);
if(moed !=""){
document.write('Jewish Holiday: '+moed);
}
}

function WriteCivilHolidays(cDay, cMonth, cYear){
holiday = holidays(cDay, cMonth, cYear);
if(holiday !=""){
document.write('Civil Holiday: '+holiday);
}
}

<!-- 
function shortMonthArray() {
this[0] = "January"; this[1] = "February"; this[2] = "March"; this[3] = "April"; this[4] = "May"; this[5] = "June";
this[6] = "July"; this[7] = "August"; this[8] = "September"; this[9] = "October"; this[10] = "November"; this[11] = "December";
return (this);
}
function getLongYear(year){
year = d.getYear();
if (year < 1000)
year+=1900;
return year;
}

function writeDate(){
shortMonths = new shortMonthArray();
d = new Date();
day = d.getDate();
month = d.getMonth();
year = d.getYear();
str =  shortMonths[month] +" " + day + ", " + getLongYear(year);
document.writeln(str);
}