/* 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', 'Iyar', 'Sivan', 'Tammuz', 'Av', 'Elul',
	'Tishrei', 'Cheshvan', 'Kislev', 'Teves', 'Shvat',
	'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');

var parshas = new makeArray(
	'Bereshit', 'Noach', 'Lech Lecha', 'Vayera', 'Chayei Sarah', 'Toldot', 'Vayetzei', 'Vayishlach', 'Vayeshev', 
	'Miketz', 'Vayigash', 'Vayechi', 'Shemot', 'Vaera', 'Bo', 'Beshalach', 'Yitro', 'Mishpatim', 'Terumah',
	'Tetzaveh', 'Ki Tisa', 'Vayakhel', 'Pekudei', 'Vayakhel-Pekudei', 'Vayikra', 'Tzav', 'Shemini', 'Tazria', 'Metzora', 
	'Tazria-Metzora', 'Achrei Mot', 'Kedoshim', 'Achrei-Kedoshim', 'Emor', 'Behar', 'Bechukosai', 'Behar-Bechukosai', 
	'Bamidbar', 'Nasso', 'Beha\'alotcha', 'Shelach', 'Korach', 'Chukat', 'Balak', 'Pinchas', 'Matot', 'Masei', 'Matot-Masei',
	'Devarim', 'Vaetchanan', 'Eikev', 'Re\'eh', 'Shoftim', 'Ki Teitzei', 'Ki Tavo', 'Nitzavim', 'Vayeilech', 'Nitzavim-Vayeilech',
	'Ha\'Azinu', 'Vesot HaBrachah');

function getHmonth(strMonth) {
	for(i=1; i<= hebMonth[0]; i++) 
		if(strMonth == hebMonth[i])
			return i;
}

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 + ' ' + hebMonth[m+1] + ' ' + 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 == 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 "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";
	else if (cmonth == 12 && cday == 25)
		return "Christmas";

	return "";
}

function moadim(cday, cmonth, cyear, hday, hmonth, dow) {
	if(hmonth == 7) {
		if(hday == 1 || hday == 2)
			return "Rosh Hashana";
		else if(hday == 3 && dow != 7)
			return "Fast of Gedalia";
		else if(hday == 4 && dow == 1)
			return "Fast of Gedalia";
		else if(hday == 10)
			return "Yom Kippur";
		else if(hday >= 15 && hday <= 21)
			return "Sukkot";
		else if(hday == 22)
			return "Shmini Atzeret";
		else if(hday == 23)
			return "Simchat Torah";
	}
	else if(hmonth == 9) {
		if(hday >= 25)
			return "Chanukah";
	}
	else if(hmonth == 10) {
		if(hday <= 2) {
			return "Chanukah";
		}
		else if(hday == 11) {
			// 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 "Chanukah";
		}
		else if(hday == 10)
			return "Fast of Tevet";
	}
	else if(hmonth == 11) {
		if(hday==15)
			return "Tu b'Shvat";
	}
	else if(hmonth == 12 || hmonth == 14) {
		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 == 13) {
		if(hday == 14)
			return "Purim Katan";
		else if(hday == 15)
			return "Shushan Purim Katan";
	}
	else if(hmonth == 1) {

		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 == 2) {
		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 == 3) {
		if(hday == 6)
			return "Shavuot";
		else if(hday == 7)
			return "Shavuot (d)";
	}
	else if(hmonth == 4) {
		if(hday == 17 && dow != 7)
			return "Fast of Tammuz";
		if(hday == 18 && dow == 1)
			return "Fast of Tammuz";
	}
	else if(hmonth == 5) {
		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 parsha(hday, hmonth) {
	switch(hmonth) {
		case 1:
		if(hday <= 7)
			return parshas[29];
		if(hday <= 14)
			return parshas[31]+"/HaGadol";
		if(hday <= 28)
			return parshas[32];
		else return parshas[34];

		case 2:
		if(hday <= 5)
			return parshas[34];
		if(hday <= 12)
			return parshas[35];
		if(hday <= 19)
			return parshas[36];
		if(hday <= 26)
			return parshas[38];
		else return parshas[39];
		
		case 3:
		if(hday <= 4)
			return parshas[39];
		if(hday <= 11)
			return parshas[40];
		if(hday <= 18)
			return parshas[41];
		if(hday <= 25)
			return parshas[42];
		else return parshas[43];
		
		case 4:
		if(hday <= 2)
			return parshas[43];
		if(hday <= 9)
			return parshas[44];
		if(hday <= 16)
			return parshas[45];
		if(hday <= 23)
			return parshas[46];
		else return parshas[47];
		
		case 5:
		if(hday <= 1)
			return parshas[47];
		if(hday <= 8)
			return parshas[49];
		if(hday <= 15)
			return parshas[50];
		if(hday <= 22)
			return parshas[51];
		if(hday <= 29)
			return parshas[52];
		else return parshas[53];
		
		case 6:
		if(hday <= 6)
			return parshas[53];
		if(hday <= 13)
			return parshas[54];
		if(hday <= 20)
			return parshas[55];
		if(hday <= 27)
			return parshas[56];
		else return parshas[57];
		
		case 7:
		if(hday <= 3)
			return parshas[59];
		if(hday <= 23)
			return parshas[60];
		if(hday >= 24)
			return parshas[1];
			
		case 8:
		if(hday <= 1)
			return parshas[2];
		if(hday <= 8)
			return parshas[3];
		if(hday <= 15)
			return parshas[4];
		if(hday <= 22)
			return parshas[5];
		if(hday <= 29)
			return parshas[6];
			
		case 9:
		if(hday <= 7)
			return parshas[7];
		if(hday <= 14)
			return parshas[8];
		if(hday <= 21)
			return parshas[9];
		if(hday <= 28)
			return parshas[10];
		else return parshas[11];
		
		case 10:
		if(hday <= 6)
			return parshas[11];
		if(hday <= 13)
			return parshas[12];
		if(hday <= 20)
			return parshas[13];
		if(hday <= 27)
			return parshas[14];
		else return parshas[15];
		
		case 11:
		if(hday <= 5)
			return parshas[15];
		if(hday <= 12)
			return parshas[16];
		if(hday <= 19)
			return parshas[17];
		if(hday <= 26)
			return parshas[18];
		else return parshas[19];
		
		case 13:
		if(hday <= 3)
			return parshas[19];
		if(hday <= 10)
			return parshas[20];
		if(hday <= 17)
			return parshas[21];
		if(hday <= 24)
			return parshas[22];
		else return parshas[23]+"/ Shekalim";
		
		case 14:
		if(hday <= 1)
			return parshas[23]+"/ Shekalim";
		if(hday <= 8)
			return parshas[25]+"/ Zachor";
		if(hday <= 15)
			return parshas[26];
		if(hday <= 22)
			return parshas[27];+"/ Parah";
		if(hday <= 29)
			return parshas[28]+"/ HaChodesh";
		else return parshas[29];
	}
	
	return "";
}

function omer(hday, hmonth) {
	if(hmonth == 1)
		if(hday >= 16)
			return hday-15;
		else return 0;
		
	if(hmonth == 2)
		return hday+15;
		
	if(hmonth == 3)
		if(hday <= 5)
			return hday+44;
			
	return 0;
}