//--------------------- Copyright Block ----------------------
/*
PrayTime.js: Prayer Times Calculator (ver 1.2.1)
Copyright (C) 2007-2010 PrayTimes.org
Developer: Hamid Zarrabi-Zadeh
License: GNU General Public License, ver 3
TERMS OF USE:
Permission is granted to use this code, with or
without modification, in any website or application
provided that credit is given to the original work
with a link back to PrayTimes.org.
This program is distributed in the hope that it will
be useful, but WITHOUT ANY WARRANTY.
PLEASE DO NOT REMOVE THIS COPYRIGHT BLOCK.
*/
//--------------------- Help and Manual ----------------------
/*
User's Manual:
http://praytimes.org/manual
Calculating Formulas:
http://praytimes.org/calculation
//------------------------ User Interface -------------------------
getPrayerTimes (date, latitude, longitude, timeZone)
getDatePrayerTimes (year, month, day, latitude, longitude, timeZone)
setCalcMethod (methodID)
setAsrMethod (methodID)
setFajrAngle (angle)
setMaghribAngle (angle)
setIshaAngle (angle)
setDhuhrMinutes (minutes) // minutes after mid-day
setMaghribMinutes (minutes) // minutes after sunset
setIshaMinutes (minutes) // minutes after maghrib
setHighLatsMethod (methodID) // adjust method for higher latitudes
setTimeFormat (timeFormat)
floatToTime24 (time)
floatToTime12 (time)
floatToTime12NS (time)
//------------------------- Sample Usage --------------------------
prayTime.setCalcMethod(prayTime.ISNA);
var times = prayTime.getPrayerTimes(new Date(), 43, -80, -5);
document.write('Sunrise = '+ times[1])
*/
//--------------------- PrayTime Class -----------------------
function PrayTime()
{
//------------------------ Constants --------------------------
// Calculation Methods
this.Jafari = 0; // Ithna Ashari
this.Karachi = 1; // University of Islamic Sciences, Karachi
this.ISNA = 2; // Islamic Society of North America (ISNA)
this.MWL = 3; // Muslim World League (MWL)
this.Makkah = 4; // Umm al-Qura, Makkah
this.Egypt = 5; // Egyptian General Authority of Survey
this.Custom = 6; // Custom Setting
this.Tehran = 7; // Institute of Geophysics, University of Tehran
// Juristic Methods
this.Shafii = 0; // Shafii (standard)
this.Hanafi = 1; // Hanafi
// Adjusting Methods for Higher Latitudes
this.None = 0; // No adjustment
this.MidNight = 1; // middle of night
this.OneSeventh = 2; // 1/7th of night
this.AngleBased = 3; // angle/60th of night
// Time Formats
this.Time24 = 0; // 24-hour format
this.Time12 = 1; // 12-hour format
this.Time12NS = 2; // 12-hour format with no suffix
this.Float = 3; // floating point number
// Time Names
this.timeNames = new Array(
'Fajr',
'Sunrise',
'Dhuhr',
'Asr',
'Sunset',
'Maghrib',
'Isha'
);
this.InvalidTime = '-----'; // The string used for invalid times
//---------------------- Global Variables --------------------
this.calcMethod = 0; // caculation method
this.asrJuristic = 0; // Juristic method for Asr
this.dhuhrMinutes = 0; // minutes after mid-day for Dhuhr
this.adjustHighLats = 1; // adjusting method for higher latitudes
this.timeFormat = 0; // time format
var lat; // latitude
var lng; // longitude
var timeZone; // time-zone
var JDate; // Julian date
//--------------------- Technical Settings --------------------
this.numIterations = 1; // number of iterations needed to compute times
//------------------- Calc Method Parameters --------------------
this.methodParams = new Array();
/* this.methodParams[methodNum] = new Array(fa, ms, mv, is, iv);
fa : fajr angle
ms : maghrib selector (0 = angle; 1 = minutes after sunset)
mv : maghrib parameter value (in angle or minutes)
is : isha selector (0 = angle; 1 = minutes after maghrib)
iv : isha parameter value (in angle or minutes)
*/
this.methodParams[this.Jafari] = new Array(16, 0, 4, 0, 14);
this.methodParams[this.Karachi] = new Array(18, 1, 0, 0, 18);
this.methodParams[this.ISNA] = new Array(15, 1, 0, 0, 15);
this.methodParams[this.MWL] = new Array(18, 1, 0, 0, 17);
this.methodParams[this.Makkah] = new Array(18.5, 1, 0, 1, 90);
this.methodParams[this.Egypt] = new Array(19.5, 1, 0, 0, 17.5);
this.methodParams[this.Tehran] = new Array(17.7, 0, 4.5, 0, 15);
this.methodParams[this.Custom] = new Array(18, 1, 0, 0, 17);
}
//-------------------- Interface Functions --------------------
// return prayer times for a given date
PrayTime.prototype.getDatePrayerTimes = function(year, month, day, latitude, longitude, timeZone)
{
this.lat = latitude;
this.lng = longitude;
this.timeZone = this.effectiveTimeZone(year, month, day, timeZone);
this.JDate = this.julianDate(year, month, day)- longitude/ (15* 24);
return this.computeDayTimes();
}
// return prayer times for a given date
PrayTime.prototype.getPrayerTimes = function(date, latitude, longitude, timeZone)
{
return this.getDatePrayerTimes(date.getFullYear(), date.getMonth()+ 1, date.getDate(),
latitude, longitude, timeZone);
}
// set the calculation method
PrayTime.prototype.setCalcMethod = function(methodID)
{
this.calcMethod = methodID;
}
// set the juristic method for Asr
PrayTime.prototype.setAsrMethod = function(methodID)
{
if (methodID < 0 || methodID > 1)
return;
this.asrJuristic = methodID;
}
// set the angle for calculating Fajr
PrayTime.prototype.setFajrAngle = function(angle)
{
this.setCustomParams(new Array(angle, null, null, null, null));
}
// set the angle for calculating Maghrib
PrayTime.prototype.setMaghribAngle = function(angle)
{
this.setCustomParams(new Array(null, 0, angle, null, null));
}
// set the angle for calculating Isha
PrayTime.prototype.setIshaAngle = function(angle)
{
this.setCustomParams(new Array(null, null, null, 0, angle));
}
// set the minutes after mid-day for calculating Dhuhr
PrayTime.prototype.setDhuhrMinutes = function(minutes)
{
this.dhuhrMinutes = minutes;
}
// set the minutes after Sunset for calculating Maghrib
PrayTime.prototype.setMaghribMinutes = function(minutes)
{
this.setCustomParams(new Array(null, 1, minutes, null, null));
}
// set the minutes after Maghrib for calculating Isha
PrayTime.prototype.setIshaMinutes = function(minutes)
{
this.setCustomParams(new Array(null, null, null, 1, minutes));
}
// set custom values for calculation parameters
PrayTime.prototype.setCustomParams = function(params)
{
for (var i=0; i<5; i++)
{
if (params[i] == null)
this.methodParams[this.Custom][i] = this.methodParams[this.calcMethod][i];
else
this.methodParams[this.Custom][i] = params[i];
}
this.calcMethod = this.Custom;
}
// set adjusting method for higher latitudes
PrayTime.prototype.setHighLatsMethod = function(methodID)
{
this.adjustHighLats = methodID;
}
// set the time format
PrayTime.prototype.setTimeFormat = function(timeFormat)
{
this.timeFormat = timeFormat;
}
// convert float hours to 24h format
PrayTime.prototype.floatToTime24 = function(time)
{
if (isNaN(time))
return this.InvalidTime;
time = this.fixhour(time+ 0.5/ 60); // add 0.5 minutes to round
var hours = Math.floor(time);
var minutes = Math.floor((time- hours)* 60);
return this.twoDigitsFormat(hours)+ ':'+ this.twoDigitsFormat(minutes);
}
// convert float hours to 12h format
PrayTime.prototype.floatToTime12 = function(time, noSuffix)
{
if (isNaN(time))
return this.InvalidTime;
time = this.fixhour(time+ 0.5/ 60); // add 0.5 minutes to round
var hours = Math.floor(time);
var minutes = Math.floor((time- hours)* 60);
var suffix = hours >= 12 ? ' pm' : ' am';
hours = (hours+ 12- 1)% 12+ 1;
return hours+ ':'+ this.twoDigitsFormat(minutes)+ (noSuffix ? '' : suffix);
}
// convert float hours to 12h format with no suffix
PrayTime.prototype.floatToTime12NS = function(time)
{
return this.floatToTime12(time, true);
}
//---------------------- Calculation Functions -----------------------
// References:
// http://www.ummah.net/astronomy/saltime
// http://aa.usno.navy.mil/faq/docs/SunApprox.html
// compute declination angle of sun and equation of time
PrayTime.prototype.sunPosition = function(jd)
{
var D = jd - 2451545.0;
var g = this.fixangle(357.529 + 0.98560028* D);
var q = this.fixangle(280.459 + 0.98564736* D);
var L = this.fixangle(q + 1.915* this.dsin(g) + 0.020* this.dsin(2*g));
var R = 1.00014 - 0.01671* this.dcos(g) - 0.00014* this.dcos(2*g);
var e = 23.439 - 0.00000036* D;
var d = this.darcsin(this.dsin(e)* this.dsin(L));
var RA = this.darctan2(this.dcos(e)* this.dsin(L), this.dcos(L))/ 15;
RA = this.fixhour(RA);
var EqT = q/15 - RA;
return new Array(d, EqT);
}
// compute equation of time
PrayTime.prototype.equationOfTime = function(jd)
{
return this.sunPosition(jd)[1];
}
// compute declination angle of sun
PrayTime.prototype.sunDeclination = function(jd)
{
return this.sunPosition(jd)[0];
}
// compute mid-day (Dhuhr, Zawal) time
PrayTime.prototype.computeMidDay = function(t)
{
var T = this.equationOfTime(this.JDate+ t);
var Z = this.fixhour(12- T);
return Z;
}
// compute time for a given angle G
PrayTime.prototype.computeTime = function(G, t)
{
var D = this.sunDeclination(this.JDate+ t);
var Z = this.computeMidDay(t);
var V = 1/15* this.darccos((-this.dsin(G)- this.dsin(D)* this.dsin(this.lat))/
(this.dcos(D)* this.dcos(this.lat)));
return Z+ (G>90 ? -V : V);
}
// compute the time of Asr
PrayTime.prototype.computeAsr = function(step, t) // Shafii: step=1, Hanafi: step=2
{
var D = this.sunDeclination(this.JDate+ t);
var G = -this.darccot(step+ this.dtan(Math.abs(this.lat- D)));
return this.computeTime(G, t);
}
//---------------------- Compute Prayer Times -----------------------
// compute prayer times at given julian date
PrayTime.prototype.computeTimes = function(times)
{
var t = this.dayPortion(times);
var Fajr = this.computeTime(180- this.methodParams[this.calcMethod][0], t[0]);
var Sunrise = this.computeTime(180- 0.833, t[1]);
var Dhuhr = this.computeMidDay(t[2]);
var Asr = this.computeAsr(1+ this.asrJuristic, t[3]);
var Sunset = this.computeTime(0.833, t[4]);;
var Maghrib = this.computeTime(this.methodParams[this.calcMethod][2], t[5]);
var Isha = this.computeTime(this.methodParams[this.calcMethod][4], t[6]);
return new Array(Fajr, Sunrise, Dhuhr, Asr, Sunset, Maghrib, Isha);
}
// compute prayer times at given julian date
PrayTime.prototype.computeDayTimes = function()
{
var times = new Array(5, 6, 12, 13, 18, 18, 18); //default times
for (var i=1; i<=this.numIterations; i++)
times = this.computeTimes(times);
times = this.adjustTimes(times);
return this.adjustTimesFormat(times);
}
// adjust times in a prayer time array
PrayTime.prototype.adjustTimes = function(times)
{
for (var i=0; i<7; i++)
times[i] += this.timeZone- this.lng/ 15;
times[2] += this.dhuhrMinutes/ 60; //Dhuhr
if (this.methodParams[this.calcMethod][1] == 1) // Maghrib
times[5] = times[4]+ this.methodParams[this.calcMethod][2]/ 60;
if (this.methodParams[this.calcMethod][3] == 1) // Isha
times[6] = times[5]+ this.methodParams[this.calcMethod][4]/ 60;
if (this.adjustHighLats != this.None)
times = this.adjustHighLatTimes(times);
return times;
}
// convert times array to given time format
PrayTime.prototype.adjustTimesFormat = function(times)
{
if (this.timeFormat == this.Float)
return times;
for (var i=0; i<7; i++)
if (this.timeFormat == this.Time12)
times[i] = this.floatToTime12(times[i]);
else if (this.timeFormat == this.Time12NS)
times[i] = this.floatToTime12(times[i], true);
else
times[i] = this.floatToTime24(times[i]);
return times;
}
// adjust Fajr, Isha and Maghrib for locations in higher latitudes
PrayTime.prototype.adjustHighLatTimes = function(times)
{
var nightTime = this.timeDiff(times[4], times[1]); // sunset to sunrise
// Adjust Fajr
var FajrDiff = this.nightPortion(this.methodParams[this.calcMethod][0])* nightTime;
if (isNaN(times[0]) || this.timeDiff(times[0], times[1]) > FajrDiff)
times[0] = times[1]- FajrDiff;
// Adjust Isha
var IshaAngle = (this.methodParams[this.calcMethod][3] == 0) ? this.methodParams[this.calcMethod][4] : 18;
var IshaDiff = this.nightPortion(IshaAngle)* nightTime;
if (isNaN(times[6]) || this.timeDiff(times[4], times[6]) > IshaDiff)
times[6] = times[4]+ IshaDiff;
// Adjust Maghrib
var MaghribAngle = (this.methodParams[this.calcMethod][1] == 0) ? this.methodParams[this.calcMethod][2] : 4;
var MaghribDiff = this.nightPortion(MaghribAngle)* nightTime;
if (isNaN(times[5]) || this.timeDiff(times[4], times[5]) > MaghribDiff)
times[5] = times[4]+ MaghribDiff;
return times;
}
// the night portion used for adjusting times in higher latitudes
PrayTime.prototype.nightPortion = function(angle)
{
if (this.adjustHighLats == this.AngleBased)
return 1/60* angle;
if (this.adjustHighLats == this.MidNight)
return 1/2;
if (this.adjustHighLats == this.OneSeventh)
return 1/7;
}
// convert hours to day portions
PrayTime.prototype.dayPortion = function(times)
{
for (var i=0; i<7; i++)
times[i] /= 24;
return times;
}
//---------------------- Misc Functions -----------------------
// compute the difference between two times
PrayTime.prototype.timeDiff = function(time1, time2)
{
return this.fixhour(time2- time1);
}
// add a leading 0 if necessary
PrayTime.prototype.twoDigitsFormat = function(num)
{
return (num <10) ? '0'+ num : num;
}
//---------------------- Julian Date Functions -----------------------
// calculate julian date from a calendar date
PrayTime.prototype.julianDate = function(year, month, day)
{
if (month <= 2)
{
year -= 1;
month += 12;
}
var A = Math.floor(year/ 100);
var B = 2- A+ Math.floor(A/ 4);
var JD = Math.floor(365.25* (year+ 4716))+ Math.floor(30.6001* (month+ 1))+ day+ B- 1524.5;
return JD;
}
// convert a calendar date to julian date (second method)
PrayTime.prototype.calcJD = function(year, month, day)
{
var J1970 = 2440588.0;
var date = new Date(year, month- 1, day);
var ms = date.getTime(); // # of milliseconds since midnight Jan 1, 1970
var days = Math.floor(ms/ (1000 * 60 * 60* 24));
return J1970+ days- 0.5;
}
//---------------------- Time-Zone Functions -----------------------
// compute local time-zone for a specific date
PrayTime.prototype.getTimeZone = function(date)
{
var localDate = new Date(date.getFullYear(), date.getMonth(), date.getDate(), 0, 0, 0, 0);
var GMTString = localDate.toGMTString();
var GMTDate = new Date(GMTString.substring(0, GMTString.lastIndexOf(' ')- 1));
var hoursDiff = (localDate- GMTDate)/ (1000* 60* 60);
return hoursDiff;
}
// return effective timezone for a given date
PrayTime.prototype.effectiveTimeZone = function(year, month, day, timeZone)
{
if (timeZone == null || typeof(timeZone) == 'undefined' || timeZone == 'auto')
timeZone = this.getTimeZone(new Date(year, month- 1, day));
return 1* timeZone;
}
//---------------------- Trigonometric Functions -----------------------
// degree sin
PrayTime.prototype.dsin = function(d)
{
return Math.sin(this.dtr(d));
}
// degree cos
PrayTime.prototype.dcos = function(d)
{
return Math.cos(this.dtr(d));
}
// degree tan
PrayTime.prototype.dtan = function(d)
{
return Math.tan(this.dtr(d));
}
// degree arcsin
PrayTime.prototype.darcsin = function(x)
{
return this.rtd(Math.asin(x));
}
// degree arccos
PrayTime.prototype.darccos = function(x)
{
return this.rtd(Math.acos(x));
}
// degree arctan
PrayTime.prototype.darctan = function(x)
{
return this.rtd(Math.atan(x));
}
// degree arctan2
PrayTime.prototype.darctan2 = function(y, x)
{
return this.rtd(Math.atan2(y, x));
}
// degree arccot
PrayTime.prototype.darccot = function(x)
{
return this.rtd(Math.atan(1/x));
}
// degree to radian
PrayTime.prototype.dtr = function(d)
{
return (d * Math.PI) / 180.0;
}
// radian to degree
PrayTime.prototype.rtd = function(r)
{
return (r * 180.0) / Math.PI;
}
// range reduce angle in degrees.
PrayTime.prototype.fixangle = function(a)
{
a = a - 360.0 * (Math.floor(a / 360.0));
a = a < 0 ? a + 360.0 : a;
return a;
}
// range reduce hours to 0..23
PrayTime.prototype.fixhour = function(a)
{
a = a - 24.0 * (Math.floor(a / 24.0));
a = a < 0 ? a + 24.0 : a;
return a;
}
//---------------------- prayTime Object -----------------------
var prayTime = new PrayTime();