// BEGIN SUNRISE / SUNSET CALCULATION.
// Convert radian angle to degrees
	function radToDeg(angleRad)
	{
		return (180.0 * angleRad / Math.PI);
	}

// Convert degree angle to radians

	function degToRad(angleDeg)
	{
		return (Math.PI * angleDeg / 180.0);
	}

//***********************************************************************/
//* Name:    calcHourAngleSunrise							*/
//* Type:    Function									*/
//* Purpose: calculate the hour angle of the sun at sunrise for the	*/
//*			latitude								*/
//* Arguments:										*/
//*   lat : latitude of observer in degrees					*/
//*	solarDec : declination angle of sun in degrees				*/
//* Return value:										*/
//*   hour angle of sunrise in radians						*/
//***********************************************************************/

	function calcHourAngleSunrise(lat, solarDec)
	{
		var latRad = degToRad(lat);
		var sdRad  = degToRad(solarDec)

		var HAarg = (Math.cos(degToRad(90.833))/(Math.cos(latRad)*Math.cos(sdRad))-Math.tan(latRad) * Math.tan(sdRad));

		var HA = (Math.acos(Math.cos(degToRad(90.833))/(Math.cos(latRad)*Math.cos(sdRad))-Math.tan(latRad) * Math.tan(sdRad)));

		return HA;		// in radians
	}

//***********************************************************************/
//* Name:    calcHourAngleSunset							*/
//* Type:    Function									*/
//* Purpose: calculate the hour angle of the sun at sunset for the	*/
//*			latitude								*/
//* Arguments:										*/
//*   lat : latitude of observer in degrees					*/
//*	solarDec : declination angle of sun in degrees				*/
//* Return value:										*/
//*   hour angle of sunset in radians						*/
//***********************************************************************/

	function calcHourAngleSunset(lat, solarDec)
	{
		var latRad = degToRad(lat);
		var sdRad  = degToRad(solarDec)

		var HAarg = (Math.cos(degToRad(90.833))/(Math.cos(latRad)*Math.cos(sdRad))-Math.tan(latRad) * Math.tan(sdRad));

		var HA = (Math.acos(Math.cos(degToRad(90.833))/(Math.cos(latRad)*Math.cos(sdRad))-Math.tan(latRad) * Math.tan(sdRad)));

		return -HA;		// in radians
	}


//***********************************************************************/
//* Name:    calcSunriseUTC								*/
//* Type:    Function									*/
//* Purpose: calculate the Universal Coordinated Time (UTC) of sunrise	*/
//*			for the given day at the given location on earth	*/
//* Arguments:										*/
//*   JD  : julian day									*/
//*   latitude : latitude of observer in degrees				*/
//*   longitude : longitude of observer in degrees				*/
//* Return value:										*/
//*   time in minutes from zero Z							*/
//***********************************************************************/

	function calcSunriseUTC(JD, latitude, longitude)
	{
		var t = calcTimeJulianCent(JD);

		// *** First pass to approximate sunrise

		var eqTime = calcEquationOfTime(t);
		var solarDec = calcSunDeclination(t);
		var hourAngle = calcHourAngleSunrise(latitude, solarDec);

		var delta = longitude - radToDeg(hourAngle);
		var timeDiff = 4 * delta;	// in minutes of time
		var timeUTC = 720 + timeDiff - eqTime;	// in minutes

		// alert("eqTime = " + eqTime + "\nsolarDec = " + solarDec + "\ntimeUTC = " + timeUTC);

		// *** Second pass includes fractional jday in gamma calc

		var newt = calcTimeJulianCent(calcJDFromJulianCent(t) + timeUTC/1440.0);
		eqTime = calcEquationOfTime(newt);
		solarDec = calcSunDeclination(newt);
		hourAngle = calcHourAngleSunrise(latitude, solarDec);
		delta = longitude - radToDeg(hourAngle);
		timeDiff = 4 * delta;
		timeUTC = 720 + timeDiff - eqTime; // in minutes

		// alert("eqTime = " + eqTime + "\nsolarDec = " + solarDec + "\ntimeUTC = " + timeUTC);

		return timeUTC;
	}

//***********************************************************************/
//* Name:    calcSolNoonUTC								*/
//* Type:    Function									*/
//* Purpose: calculate the Universal Coordinated Time (UTC) of solar	*/
//*		noon for the given day at the given location on earth		*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//*   longitude : longitude of observer in degrees				*/
//* Return value:										*/
//*   time in minutes from zero Z							*/
//***********************************************************************/

	function calcSolNoonUTC(t, longitude)
	{
		var newt = calcTimeJulianCent(calcJDFromJulianCent(t) + 0.5 + longitude/360.0);

		var eqTime = calcEquationOfTime(newt);
		var solarNoonDec = calcSunDeclination(newt);
		var solNoonUTC = 720 + (longitude * 4) - eqTime; // min

		return solNoonUTC;
	}

//***********************************************************************/
//* Name:    calcSunsetUTC								*/
//* Type:    Function									*/
//* Purpose: calculate the Universal Coordinated Time (UTC) of sunset	*/
//*			for the given day at the given location on earth	*/
//* Arguments:										*/
//*   JD  : julian day									*/
//*   latitude : latitude of observer in degrees				*/
//*   longitude : longitude of observer in degrees				*/
//* Return value:										*/
//*   time in minutes from zero Z							*/
//***********************************************************************/

	function calcSunsetUTC(JD, latitude, longitude)
	{
		var t = calcTimeJulianCent(JD);

		// First calculates sunrise and approx length of day

		var eqTime = calcEquationOfTime(t);
		var solarDec = calcSunDeclination(t);
		var hourAngle = calcHourAngleSunset(latitude, solarDec);

		var delta = longitude - radToDeg(hourAngle);
		var timeDiff = 4 * delta;
		var timeUTC = 720 + timeDiff - eqTime;

		// first pass used to include fractional day in gamma calc

		var newt = calcTimeJulianCent(calcJDFromJulianCent(t) + timeUTC/1440.0);
		eqTime = calcEquationOfTime(newt);
		solarDec = calcSunDeclination(newt);
		hourAngle = calcHourAngleSunset(latitude, solarDec);

		delta = longitude - radToDeg(hourAngle);
		timeDiff = 4 * delta;
		timeUTC = 720 + timeDiff - eqTime; // in minutes

		return timeUTC;
	}


//***********************************************************************/
//* Name:    timeString									*/
//* Type:    Function									*/
//* Purpose: convert time of day in minutes to a zero-padded string	*/
//*		suitable for printing to the form text fields			*/
//* Arguments:										*/
//*   minutes : time of day in minutes						*/
//* Return value:										*/
//*   string of the format HH:MM:SS, minutes and seconds are zero padded*/
//***********************************************************************/

	function timeString(minutes)
	// timeString returns a zero-padded string (HH:MM:SS) given time in minutes
	{
		var floatHour = minutes / 60;
		var hour = Math.floor(floatHour);
		var floatMinute = 60 * (floatHour - Math.floor(floatHour));
		var minute = Math.floor(floatMinute);
		var floatSec = 60 * (floatMinute - Math.floor(floatMinute));
		var second = Math.floor(floatSec);

		var timeStr = hour + ":";
        
        //if (second < 30) // rounding
			//minute += 0;
		//else
			//minute += 1;

		if (minute < 10)	//	i.e. only one digit
			timeStr += "0" + minute + ":";
		else
			timeStr += minute + ".";

		if (second < 10)	//	i.e. only one digit
			timeStr += "0" + second;
		else
			timeStr += second ;

		return timeStr;
	}

//***********************************************************************/
//* Name:    calcSunEqOfCenter							*/
//* Type:    Function									*/
//* Purpose: calculate the equation of center for the sun			*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   in degrees										*/
//***********************************************************************/


	function calcSunEqOfCenter(t)
	{
		var m = calcGeomMeanAnomalySun(t);

		var mrad = degToRad(m);
		var sinm = Math.sin(mrad);
		var sin2m = Math.sin(mrad+mrad);
		var sin3m = Math.sin(mrad+mrad+mrad);

		var C = sinm * (1.914602 - t * (0.004817 + 0.000014 * t)) + sin2m * (0.019993 - 0.000101 * t) + sin3m * 0.000289;
		return C;		// in degrees
	}

//***********************************************************************/
//* Name:    calcSunTrueLong								*/
//* Type:    Function									*/
//* Purpose: calculate the true longitude of the sun				*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   sun's true longitude in degrees						*/
//***********************************************************************/


	function calcSunTrueLong(t)
	{
		var l0 = calcGeomMeanLongSun(t);
		var c = calcSunEqOfCenter(t);

		var O = l0 + c;
		return O;		// in degrees
	}

//***********************************************************************/
//* Name:    calcSunApparentLong							*/
//* Type:    Function									*/
//* Purpose: calculate the apparent longitude of the sun			*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   sun's apparent longitude in degrees						*/
//***********************************************************************/

	function calcSunApparentLong(t)
	{
		var o = calcSunTrueLong(t);

		var omega = 125.04 - 1934.136 * t;
		var lambda = o - 0.00569 - 0.00478 * Math.sin(degToRad(omega));
		return lambda;		// in degrees
	}

//***********************************************************************/
//* Name:    calcSunDeclination							*/
//* Type:    Function									*/
//* Purpose: calculate the declination of the sun				*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   sun's declination in degrees							*/
//***********************************************************************/

	function calcSunDeclination(t)
	{
		var e = calcObliquityCorrection(t);
		var lambda = calcSunApparentLong(t);

		var sint = Math.sin(degToRad(e)) * Math.sin(degToRad(lambda));
		var theta = radToDeg(Math.asin(sint));
		return theta;		// in degrees
	}

//***********************************************************************/
//* Name:    calGeomAnomalySun							*/
//* Type:    Function									*/
//* Purpose: calculate the Geometric Mean Anomaly of the Sun		*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   the Geometric Mean Anomaly of the Sun in degrees			*/
//***********************************************************************/

	function calcGeomMeanAnomalySun(t)
	{
		var M = 357.52911 + t * (35999.05029 - 0.0001537 * t);
		return M;		// in degrees
	}

//***********************************************************************/
//* Name:    calcEccentricityEarthOrbit						*/
//* Type:    Function									*/
//* Purpose: calculate the eccentricity of earth's orbit			*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   the unitless eccentricity							*/
//***********************************************************************/


	function calcEccentricityEarthOrbit(t)
	{
		var e = 0.016708634 - t * (0.000042037 + 0.0000001267 * t);
		return e;		// unitless
	}

//***********************************************************************/
//* Name:    calGeomMeanLongSun							*/
//* Type:    Function									*/
//* Purpose: calculate the Geometric Mean Longitude of the Sun		*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   the Geometric Mean Longitude of the Sun in degrees			*/
//***********************************************************************/

	function calcGeomMeanLongSun(t)
	{
		var L0 = 280.46646 + t * (36000.76983 + 0.0003032 * t);
		while(L0 > 360.0)
		{
			L0 -= 360.0;
		}
		while(L0 < 0.0)
		{
			L0 += 360.0;
		}
		return L0;		// in degrees
	}


//***********************************************************************/
//* Name:    calcMeanObliquityOfEcliptic						*/
//* Type:    Function									*/
//* Purpose: calculate the mean obliquity of the ecliptic			*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   mean obliquity in degrees							*/
//***********************************************************************/

	function calcMeanObliquityOfEcliptic(t)
	{
		var seconds = 21.448 - t*(46.8150 + t*(0.00059 - t*(0.001813)));
		var e0 = 23.0 + (26.0 + (seconds/60.0))/60.0;
		return e0;		// in degrees
	}

//***********************************************************************/
//* Name:    calcObliquityCorrection						*/
//* Type:    Function									*/
//* Purpose: calculate the corrected obliquity of the ecliptic		*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   corrected obliquity in degrees						*/
//***********************************************************************/

	function calcObliquityCorrection(t)
	{
		var e0 = calcMeanObliquityOfEcliptic(t);

		var omega = 125.04 - 1934.136 * t;
		var e = e0 + 0.00256 * Math.cos(degToRad(omega));
		return e;		// in degrees
	}

//***********************************************************************/
//* Name:    calcJD									*/
//* Type:    Function									*/
//* Purpose: Julian day from calendar day						*/
//* Arguments:										*/
//*   year : 4 digit year								*/
//*   month: January = 1								*/
//*   day  : 1 - 31									*/
//* Return value:										*/
//*   The Julian day corresponding to the date					*/
//* Note:											*/
//*   Number is returned for start of day.  Fractional days should be	*/
//*   added later.									*/
//***********************************************************************/

	function calcJD(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;
	}

//***********************************************************************/
//* Name:    calcEquationOfTime							*/
//* Type:    Function									*/
//* Purpose: calculate the difference between true solar time and mean	*/
//*		solar time									*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   equation of time in minutes of time						*/
//***********************************************************************/

	function calcEquationOfTime(t)
	{
		var epsilon = calcObliquityCorrection(t);
		var l0 = calcGeomMeanLongSun(t);
		var e = calcEccentricityEarthOrbit(t);
		var m = calcGeomMeanAnomalySun(t);

		var y = Math.tan(degToRad(epsilon)/2.0);
		y *= y;

		var sin2l0 = Math.sin(2.0 * degToRad(l0));
		var sinm   = Math.sin(degToRad(m));
		var cos2l0 = Math.cos(2.0 * degToRad(l0));
		var sin4l0 = Math.sin(4.0 * degToRad(l0));
		var sin2m  = Math.sin(2.0 * degToRad(m));

		var Etime = y * sin2l0 - 2.0 * e * sinm + 4.0 * e * y * sinm * cos2l0
				- 0.5 * y * y * sin4l0 - 1.25 * e * e * sin2m;

		return radToDeg(Etime)*4.0;	// in minutes of time
	}

//***********************************************************************/
//* Name:    calcJDFromJulianCent							*/
//* Type:    Function									*/
//* Purpose: convert centuries since J2000.0 to Julian Day.			*/
//* Arguments:										*/
//*   t : number of Julian centuries since J2000.0				*/
//* Return value:										*/
//*   the Julian Day corresponding to the t value				*/
//***********************************************************************/

	function calcJDFromJulianCent(t)
	{
		var JD = t * 36525.0 + 2451545.0;
		return JD;
	}

//***********************************************************************/
//* Name:    calcTimeJulianCent							*/
//* Type:    Function									*/
//* Purpose: convert Julian Day to centuries since J2000.0.			*/
//* Arguments:										*/
//*   jd : the Julian Day to convert						*/
//* Return value:										*/
//*   the T value corresponding to the Julian Day				*/
//***********************************************************************/

	function calcTimeJulianCent(jd)
	{
		var T = (jd - 2451545.0)/36525.0;
		return T;
	}

    function dst_calculator() {
    var dst = 0;       // set to 1 for daylight savings time
                       // update this as you go on and off daylight saving time


    var gmt = new Date;
    gmt.setDate(gmt.getDate() + window.ADDDAYS); // ADDED BY GLENN
    var sec_sun_mar = new Date;
    var first_sun_nov = new Date;

    sec_sun_mar.setMonth(2); // Sets Month to March for calculation 0=Jan, 1=Feb, etc
    sec_sun_mar.setDate(8); // Sets day to 8 for calculation since second Sunday always has to be at least 8 days into the month
    day = sec_sun_mar.getDay(); // What day of week is the 8th?
    days_to_add = day;
    if (day != 0)  days_to_add = (7 - day);
    sec_sun_mar.setDate(8 + days_to_add); // Second Sunday.  If 8th day is Sunday we add 0, if Sat add 1, if Fri add 2 etc


    first_sun_nov.setMonth(10); // Sets Month to November for calculation 0=Jan, 1=Feb, etc
    first_sun_nov.setDate(1); // Sets day to 1 for calculation since first Sunday can be first day of the month
    var day = first_sun_nov.getDay();// day of week of 1st
    days_to_add = day;
    if (day !=0)  days_to_add = (7 - day);
    first_sun_nov.setDate(1 + days_to_add); // first Sunday.  If 1st day is Sunday we add 0, if Sat add 1, if Fri add 2 etc

    if (gmt >= sec_sun_mar && gmt < first_sun_nov ) dst = 1;

 	return (dst);

    }

    var curDate = new Date();
    curDate.setDate(curDate.getDate() + window.ADDDAYS); // ADDED BY GLENN
    // Ref: http://www.webreference.com/js/scripts/basic_date/
    var days = new Array( 'Sun','Mon','Tue', 'Wed','Thu','Fri','Sat');
    var months = new Array( 'Jan','Feb','Mar','Apr','May', 'Jun','Jul','Aug','Sep','Oct', 'Nov','Dec');
    var curDateString = days[curDate.getDay()] + ", " + curDate.getDate() + " " + months[curDate.getMonth()] + " " + curDate.getFullYear();
    var curDateStr
    var JD = calcJD( curDate.getFullYear(), curDate.getMonth() + 1, curDate.getDate() );
    var T = calcTimeJulianCent(JD);
    var dst =  dst_calculator();
    if (dst == 0 ) whatisdst ='You are on Standard Time.';
    if (dst == 1 ) whatisdst ='You are on Daylight Savings Time.';