/*
 JavaScript Sun Table Calculator
© 2001 Juergen Giesen
http://www.jgiesen.de
*/



var dat, JD, UT, offset, dIM, RA, EOT
var lat, longit, offset, locOffset;
var monthName = new Array('Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec');
var dayName = new Array('Mon','Tue','Wed','Thu','Fri','Sat','Sun');

var ok, OK, LatLong, locName, url;
var ns, ew, timezoneString, lengthDayString;
var string1="ex1";
var deg = String.fromCharCode(176);

var hours, utHours, minutes, seconds, day, utDay, month, utMonth, year, utYear;

function setMenu(d, m, y, h, min) {
 if (d>0)
	 document.myform.Tag.options[d-1].selected=true; else alert(d);
 if (m>0)
	 document.myform.Monat.options[m-1].selected=true; else alert(m);
	document.myform.Jahr.options[y-1900].selected=true;
	document.myform.Stunde.options[h].selected=true;
	document.myform.Minute.options[min].selected=true;
}

function currentTime() {

 var curDat = new Date();
 var curOffset = curDat.getTimezoneOffset();
 if (curOffset>=1320) curOffset=curOffset-1440;
 var dLocOffset=-curOffset/60;

 utHours = curDat.getHours() - dLocOffset;
 /*
LatLong =  document.myform.location.options[document.myform.location.selectedIndex].value;
 if (document.myform.location.selectedIndex != 0) getLocation(LatLong);
 var nn=2*locOffset;
 if (locOffset>0) nn=nn-1;
 document.myform.timezone.options[Math.abs(nn)].selected=true;
*/
 hours = utHours + locOffset;
 if (hours<0) hours+=24;
 if (hours>23) hours-=24;
 minutes = curDat.getMinutes();
 seconds = curDat.getSeconds();
 year = curDat.getYear();
 if (year<1900) year=year+1900;
 month = curDat.getMonth()+1;
 day = curDat.getDate();

 utMinutes = minutes;
 utMonth = month;
 utYear = year;

 document.myform.text1.value = writeDateTime(hours,day,month);
 document.myform.UTime.value = writeDateTime(utHours,utDay,utMonth);

 setMenu(day, month, year, hours, minutes);
}

function writeDateTime(h, d, m) {

 var str = " " + year+", " + document.myform.Monat.options[m-1].value+" ";
 if (d<10) str=str+"0"+d; else str=str+d;
 str=str+" at  ";
 if (h<10) str=str+"0"+h+":"; else  str=str+h+":";
 if (minutes<10) str=str+"0"+minutes; else str=str+minutes;
 if (seconds<10) str = str + ":0"+seconds; else  str = str + ":"+seconds;
 return str;
}

function getDateTime() {

 var LatLong = document.myform.location.options[document.myform.location.selectedIndex].value;
 var n=LatLong.length;
 var latStr="", s=0, s1=0, star=0;
 for (var i=0; i<n; i++) {if (LatLong.charAt(i)=='/') {s=i;break}};
 for (var i=s+1; i<n; i++) {if (LatLong.charAt(i)=='/') {s1=i;break}};
 for (var i=s1+1; i<n; i++) {if (LatLong.charAt(i)=='*') {star=i;break}};
 locName = LatLong.substring(star+1,n);
 url = this.location.toString();
 OK = "OMED";

var tzString = LatLong.substring(s1+1,star);
locOffset=Number(tzString);

//getLocation(LatLong);

var nn=2*locOffset;
 if (locOffset>0) nn=nn-1;
 document.myform.timezone.options[Math.abs(nn)].selected=true;

 //offset=-60*document.myform.timezone.options[document.myform.timezone.selectedIndex].value;
 //locOffset = -offset/60;

//alert(locOffset)

ok = OK.charAt(3)+OK.charAt(2)+OK.charAt(1)+OK.charAt(0);		


 var dat = new Date();

//alert(dat.toString())

 hours = dat.getHours(); 

 var curOffset = dat.getTimezoneOffset();
 
 //Daylight Savings Time
 var dst1 = 0;
 if (document.myform.dst0.options.selectedIndex==0){dst1 = 1};
 
 if (curOffset>=1320) curOffset=curOffset-1440;
 curOffset=-curOffset/60;

 hours = hours - curOffset + locOffset;
 if (hours>=24) {hours=hours-24;day=day+1;}
 daysInMonth(month,year);
 if (day>dIM) {day=1;month=month+1;}
 if (month>12) {month=1;year=year+1;}

 if (hours<0) {hours=hours+24;day=day-1;}
 daysInMonth(month,year);
 if (day<1) {day=dIM;month=month-1;}
 if (month<1) {month=1;year=year-1;}

utHours = hours - locOffset;

 if (utHours>=24) {utHours=utHours-24;utDay=utDay+1;}
 if (utDay>dIM) {utDay=1;utMonth=utMonth+1;}
 if (utMonth>12) {utMonth=1;utYear=utYear+1;}


 if (utHours<0) {utHours=utHours+24;utDay=utDay-1;}
 if (utDay<1) {utDay=dIM;utMonth=utMonth-1;}
 if (utMonth<1) {utMonth=1;utYear=utYear-1;}


//alert(hours)
//alert(dat.getTimezoneOffset())
 minutes = dat.getMinutes();
 seconds = dat.getSeconds();
 year = dat.getYear();
 if (year<1900) year=year+1900;
 month = dat.getMonth()+1;
 day = dat.getDate();

 var millis = dat.getTime();
 millis=millis-locOffset*3600*1000;

 var d = new Date(millis);
 
//utHours = d.getHours();

 utDay = d.getDate();
 utMonth = d.getMonth()+1;
 utYear = d.getYear();
 if (utYear<1900) utYear=utYear+1900;

 UT = utHours + minutes/60 + seconds/3600;

 hours = hours + dst1;

 document.myform.text1.value = writeDateTime(hours,day,month);
 document.myform.UTime.value = writeDateTime(utHours,utDay,utMonth);


 setMenu(day, month, year, hours, minutes);

 myMonth = month;

 //EOT = eot(utDay,utMonth,utYear,UT);
 theJulDay();
}

function ut() {
 utHours = hours - locOffset;
}

function setUT() {
 
 var theDate = new Date(year,month-1,day,hours,minutes,seconds);
 var millis = theDate.getTime();

 millis=millis-locOffset*3600*1000;

 var d = new Date(millis);
 utHours = d.getHours();
 utMinutes = d.getMinutes();
 utDay = d.getDate();
 utMonth = d.getMonth()+1;
 utYear = d.getYear();
 if (utYear<1900) utYear=utYear+1900;

 UT = utHours + utMinutes/60 + seconds/3600;

 document.myform.text1.value = writeDateTime(hours,day,month);
 document.myform.UTime.value = writeDateTime(utHours,utDay,utMonth);

 //EOT = eot(utDay,utMonth,utYear,UT);
}


function declination(day, month, year, UT) {

 var K = Math.PI/180.0;
 var jd =JulDay(day, month, year, UT);
 var T = (jd - 2451545.0)/36525.0;
 var L0 = 280.46645 + (36000.76983 + 0.0003032*T)*T;
 var M = 357.52910 + (35999.05030 - (0.0001559*T + 0.00000048*T)*T)*T; 
 M = K*M;
 var C = (1.914600 - 0.004817*T - 0.000014*T*T)*Math.sin(M) + (0.019993 - 0.000101*T)*Math.sin(2*M) + 0.000290*Math.sin(3*M);
 var theta = L0 + C;
 var omega = 125.04 - 1934.136*T;
 var lambda = theta - 0.00569 - 0.00478*Math.sin(K*omega);
 var eps0 =  23.0 + 26.0/60.0 + 21.448/3600.0 - (46.8150*T + 0.00059*T*T - 0.001813*T*T*T)/3600;
 var eps = eps0 + 0.00256*Math.cos(K*omega);
 var declin = Math.sin(K*eps)*Math.sin(K*lambda);
 declin = Math.asin(declin)/K;
 RA =Math.atan2(Math.cos(K*eps)*Math.sin(K*lambda), Math.cos(K*lambda))/K;
 if (RA<0) RA=RA+360;
 return declin;
}

function getLocation(LatLong) {

 var n=LatLong.length;
 var latStr="", s=0, s1=0, star=0;
 for (var i=0; i<n; i++) {if (LatLong.charAt(i)=='/') {s=i;break}};
 for (var i=s+1; i<n; i++) {if (LatLong.charAt(i)=='/') {s1=i;break}};
 for (var i=s1+1; i<n; i++) {if (LatLong.charAt(i)=='*') {star=i;break}};

 var latStr = LatLong.substring(0,s);
 //document.myform.latitude.value=Math.abs(latStr);
 lat = Number(latStr);
 //if (lat>=0) {ns=" N";  document.myform.NorthSouth.options[0].selected=true;}
 //else {ns=" S"; document.myform.NorthSouth.options[1].selected=true;}

 var longStr = LatLong.substring(s+1,s1);
 document.myform.longitude.value=Math.abs(longStr);
 longit = Number(longStr);
 if (longit>=0) {ew=" E"; document.myform.EastWest.options[0].selected=true;}
 else {ew=" W"; document.myform.EastWest.options[1].selected=true;}
 var tzString = LatLong.substring(s1+1,star);
 locOffset=Number(tzString);


 var nn=2*locOffset;
 if (locOffset>0) nn=nn-1;
 document.myform.timezone.options[Math.abs(nn)].selected=true;

 locName = LatLong.substring(star+1,n);

 var millis = Date.UTC(year,utMonth-1,utDay,utHours,minutes,seconds);
 millis=millis+locOffset*3600*1000;

 var d = new Date();
 var doffset=d.getTimezoneOffset();
 if (doffset>=1320) doffset=doffset-1440;
 var dlocOffset=-doffset/60;
 millis=millis-dlocOffset*3600*1000;
 d = new Date(millis);
 hours = d.getHours();
 day = d.getDate();
 month = d.getMonth()+1;
 year = d.getYear();
 if (year<1900) year=year+1900;

 setMenu(day, month, year, hours, minutes);

 if (locOffset>=0) timezoneString="GMT + " + locOffset;
 else  timezoneString="GMT  " + locOffset;

 //UT = utHours + minutes/60 + seconds/3600;
 document.myform.text1.value = writeDateTime(hours,day,month);

 calculate();
}


function HoursMinutes(time) {
 var t=time;
 time=Math.abs(time);
 var min=Math.round(60*(time-Math.floor(time)));
 var str;
 if (min>=10) str=Math.floor(time)+":"+min;
 else  str=Math.floor(time)+":0"+min;
 if (min==60) str=Math.floor(time+1)+":00";
 if (t<0) return "-"+str; else return str;
}

function HoursMinutesSeconds(time) {

 var h = Math.floor(time);
 var min = Math.floor(60.0*frac(time));
 var secs = Math.round(60.0*(60.0*frac(time)-min));

 var str;
 if (min>=10) str=h+":"+min;
 else  str=h+":0"+min;
 //if (min==60) str=(h+1)+":00";
 if (secs<10) str = str + ":0"+secs;
 else str = str + ":"+secs;
 return " " + str;

}


function DegreesMinutes(time) {
 var t=time;
 time=Math.abs(time);
 var min=Math.round(60*(time-Math.floor(time)));
 var str;
 //if (min>=10) str=Math.floor(time)+" deg "+min + " min";
 //else  str=Math.floor(time)+" deg 0"+min + " min";
 if (min>=10) str=Math.floor(time)+deg+" "+min + "'";
 else  str=Math.floor(time)+deg+" 0"+min + "'";
 if (min==60) str=Math.floor(time+1)+":00" + "'";
 if (t<0) return "-"+str; else return str;
}

function TZone() {
 
 var index=document.myform.timezone.selectedIndex;
 var delta = document.myform.timezone.options[index].value;

var dat = new Date(Date.UTC(year,month-1,utDay,utHours,minutes,seconds));
 var millis = Date.UTC(year,month-1,day,utHours,minutes,seconds);
 var theOffset = dat.getTimezoneOffset();
 if (theOffset>=1320) theOffset=theOffset-1440;
 var dLocOffset=-theOffset/60;

 millis = millis - (dLocOffset -delta)*3600*1000;

 var dat1 = new Date(millis);
 //hours = dat1.getHours();
 minutes = dat1.getMinutes();
 seconds = dat1.getSeconds();
 year = dat1.getYear();
 if (year<1900) year=year+1900;
 month = dat1.getMonth()+1;


 day = dat1.getDate();

 if (delta==0) {day=utDay;month=utMonth;}


 if (delta>0) {

  if ((month>utMonth) && (Number(utHours)+Number(delta)>=24))
   {month=utMonth; day=utDay+1; daysInMonth(month,year); if (day>dIM) {day=1;month=month+1;};};


 if ((month==utMonth) || (Number(utHours)+Number(delta)<24))
  {
  if (day>utDay+1) {day=day-1;};
  if (month>utMonth) {day=1};
  if (Number(utHours)+Number(delta)<24) {day=utDay; month=utMonth; year=utYear;}
  if ((year>utYear)  && (day>1)) {day=day-1;}
  }
}


 if (delta<0) {

 daysInMonth(month,year);
 if ((day==dIM) && (utDay==2)) {day=1;month=utMonth}; 


 if ((day!=dIM) && (utDay!=2)) {
 if (day<utDay-1) day=day+1;
  if (month<utMonth) {daysInMonth(month,year);day=dIM}

  if (Number(utHours)+Number(delta)>=0) {day=utDay; month=utMonth;}

  if (year<utYear)  {if (day<31) day=day+1;}
 }
}

}

function getTZone() {
 
 var index=document.myform.timezone.selectedIndex;
 var delta = document.myform.timezone.options[index].value;

 var dat = new Date(Date.UTC(year,month-1,utDay,utHours,minutes,seconds));
 var millis = Date.UTC(year,month-1,day,utHours,minutes,seconds);
 var theOffset = dat.getTimezoneOffset();
 if (theOffset>=1320) theOffset=theOffset-1440;
 var dLocOffset=-theOffset/60;

 millis = millis - (dLocOffset -delta)*3600*1000;

 var dat1 = new Date(millis);
 hours = dat1.getHours();
 minutes = dat1.getMinutes();
 seconds = dat1.getSeconds();
 year = dat1.getYear();
 if (year<1900) year=year+1900;
 month = dat1.getMonth()+1;

 day = dat1.getDate();

 if (delta==0) {day=utDay;month=utMonth;}

 if (delta>0) {

  if ((month>utMonth) && (Number(utHours)+Number(delta)>=24))
   {month=utMonth; day=utDay+1; daysInMonth(month,year); if (day>dIM) {day=1;month=month+1;};};

 if ((month==utMonth) || (Number(utHours)+Number(delta)<24))
  {
  if (day>utDay+1) {day=day-1;};
  if (month>utMonth) {day=1};
  if (Number(utHours)+Number(delta)<24) {day=utDay; month=utMonth; year=utYear;}
  if ((year>utYear)  && (day>1)) {day=day-1;}
  }
}


 if (delta<0) {

 daysInMonth(month,year);
 if ((day==dIM) && (utDay==2)) {day=1;month=utMonth}; 

 if ((day!=dIM) && (utDay!=2)) {
 if (day<utDay-1) day=day+1;
  if (month<utMonth) {daysInMonth(month,year);day=dIM}

  if (Number(utHours)+Number(delta)>=0) {day=utDay; month=utMonth;}

  if (year<utYear)  {if (day<31) day=day+1;}
 }
}

 setMenu(day, month, year, hours, minutes);
 document.myform.text1.value = writeDateTime(hours,day,month);

 calculate();

}


function daysInMonth(m, y) {
	var n=31
	m=m-1
	if ((m==0) || (m==2) || (m==4) || (m==6) || (m==7) || (m==9) || (m==11))  n=31
	if ((m==3) || (m==5) || (m==8) || (m==10))  n=30;
	if (m==1) {
		n=28;
		if ((y % 4) == 0) n=29
		if ((y % 100) == 0) n=28
		if ((y % 400) == 0) n=29
		}
	dIM=n;
	
}



function calculate() {

 TZone();

 var dat1 = new Date();
 seconds = dat1.getSeconds();
 if (seconds==0) {minutes=minutes+1; if (minutes==60) 
 {minutes=0;
 hours=hours+1;
 utHours=utHours+1;
 if (hours==24) {hours=0;day=day+1;}
 if (utHours==24) {utHours=0;utDay=utDay+1;}
 daysInMonth(month,year);
 if (day>dIM) {day=1;month=month+1;}
 if (utDay>dIM) {utDay=1;utMonth=utMonth+1;}
 if (month>12) {month=1;year=year+1;}
 if (utMonth>12) {utMonth=1;utYear=utYear+1;}
 }
 } // if (seconds==0)
if (month==1 && day==1) {year=year+1};
 UT = utHours + minutes/60 + seconds/3600;

 var str = " " + Math.round(1000*declination(utDay,utMonth,utYear,UT))/1000;
 document.myform.declinText.value=str;

 //lat = document.myform.latitude.value;
 longit = document.myform.longitude.value;
 if (document.myform.EastWest.selectedIndex==1) longit=-Math.abs(longit);
 //if (document.myform.NorthSouth.selectedIndex==1) lat=-Math.abs(lat);

 EOT = eot(utDay,utMonth,utYear,UT);
 str = " " + EOT;
 document.myform.eotText.value=str;

 theJulDay();

 document.myform.text1.value = writeDateTime(hours,day,month);
 document.myform.UTime.value = writeDateTime(utHours,utDay,utMonth);
 
 document.myform.LMST.value=LM_Sidereal_Time(JulDay (day, month, year, UT),longit);
 setMenu(day, month, year, hours, minutes);

 if ((url.lastIndexOf(String.fromCharCode(106,103,105,101,115))!=-1)  && (url.lastIndexOf(string1)==-1)) {document.myform.LMST.value=ok};
}


function theDay() {
 daysInMonth(month,year);
 var index=document.myform.Tag.selectedIndex;

 if (index<dIM) day= index + 1;
 else {day= dIM; document.myform.Tag.options[dIM-1].selected=true};

 setUT();
 //calculate();
}

function theMonth() {
 month = Number(document.myform.Monat.selectedIndex)+Number(1);
 theDay();
 //calculate();
}

function theYear() {
 year = document.myform.Jahr.selectedIndex + 1900;
 theDay();
 //calculate();
}

function theHour() {
 hours = document.myform.Stunde.selectedIndex;
//alert(hours)
}


function theMinute() {
 minutes = document.myform.Minute.selectedIndex;
 seconds = 0;
}

function theJulDay() {
 jd = JulDay (utDay, utMonth, utYear, UT)
	document.myform.JulDayText.value=" " + Math.round(100000*jd)/100000	;
}

/*
function JulDay (date, month, year, UT){
 if (year<1900) year=year+1900
 if (month<=2) {month=month+12; year=year-1}
 A = Math.floor(year/100);
 B = -13;
 JD =  Math.floor(365.25*(year+4716)) + Math.floor(30.6001*(month+1)) + date + B -1524.5 + UT/24.0;
 return JD
}
*/

function JulDay (d, m, y, u){
 if (y<1900) y=y+1900
 if (m<=2) {m=m+12; y=y-1}
 A = Math.floor(y/100);
 JD =  Math.floor(365.25*(y+4716)) + Math.floor(30.6001*(m+1)) + d - 13 -1524.5 + u/24.0;
 return JD
}


function theDateTime() {

 theDay();
 theMonth();
 theYear();
 theHour();
 theMinute();
 setUT();
 theJulDay();
 calculate();

}


function sunL(T){
	var L = 280.46645 + 36000.76983*T + 0.0003032*T*T	
	L = L % 360		
	if (L<0) L = L + 360
	return L			
}

function deltaPSI(T){
	var K = Math.PI/180.0
	var deltaPsi, omega, LS, LM				
	LS = sunL(T)	
	LM = 218.3165 + 481267.8813*T		
	LM = LM % 360	
	if (LM<0) LM = LM + 360		
	omega = 125.04452 - 1934.136261*T + 0.0020708*T*T + T*T*T/450000
	deltaPsi = -17.2*Math.sin(K*omega) - 1.32*Math.sin(K*2*LS) - 0.23*Math.sin(K*2*LM) + 0.21*Math.sin(K*2*omega)
	deltaPsi = deltaPsi/3600.0		
	return deltaPsi	
}
	
function EPS(T) {
	var K = Math.PI/180.0
	var LS = sunL(T)
	var LM = 218.3165 + 481267.8813*T	
	var eps0 =  23.0 + 26.0/60.0 + 21.448/3600.0 - (46.8150*T + 0.00059*T*T - 0.001813*T*T*T)/3600
	var omega = 125.04452 - 1934.136261*T + 0.0020708*T*T + T*T*T/450000		
	var deltaEps = (9.20*Math.cos(K*omega) + 0.57*Math.cos(K*2*LS) + 0.10*Math.cos(K*2*LM) - 0.09*Math.cos(K*2*omega))/3600
	return eps0 + deltaEps	
}
	
function eot(date, month, year, UT) {		
	var K = Math.PI/180.0
	var  T = (JulDay(date, month, year, UT) - 2451545.0) / 36525.0		
	var eps = EPS(T);
 var dummy = declination(date, month, year, UT);
	var LS = sunL(T)
	var deltaPsi = deltaPSI(T)						
	var E = LS - 0.0057183 - RA + deltaPsi*Math.cos(K*eps)		
	if (E>5) E = E - 360.0		
	E = E*4; // deg. to min		
	E = Math.round(1000*E)/1000								
	return E		
}



function getLongitude() {
//alert(longit)
 str=document.myform.longitude.value;
 var n=str.length;
 for (var i=0; i<n; i++) {
 c=str.charAt(i);
 if ((c!='0') && (c!='1')  && (c!='2') && (c!='3') && (c!='4') && (c!='5') && (c!='6') && (c!='7') && (c!='8') && (c!='9')  && (c!='+') && (c!='.')) {alert("Error on longitude value !"+"\n"+"Enter decimal degree value, e.g.:"+"\n"+" 8.34 if East, or -72.34 if West.");document.myform.longitude.value=0; break;};}
 if (Math.abs(Number(str))>180) {alert("Longitude must less or equal to 180 degrees !"); document.myform.longitude.value=0; };
 longit =  Number(str);
 //if (document.myform.NorthSouth.selectedIndex==1) lat=-lat;
 if (document.myform.EastWest.selectedIndex==1) longit=-Math.abs(longit);
 if (longit>=0) ew=" E"; else ew=" W";
 document.myform.location.options[0].selected=true;
 calculate();
}




function EW() {
 if (document.myform.EastWest.selectedIndex==0) longit=Math.abs(longit);
 else  longit=-Math.abs(longit);
 locName="User Input";
 document.myform.location.options[0].selected=true;
 locName="User Input";
 calculate()
}


function dayString(jd){
	var num;
	var dayName = new Array('Mon','Tue','Wed','Thu','Fri','Sat','Sun');
	  	num = jd+0.5;
	  	num = num - Math.floor(num/7)*7;
	   
		return dayName[Math.floor(num)];
	}

function GM_Sidereal_Time (jd) {	
		var t_eph, ut, MJD0, MJD;
				
		MJD = jd - 2400000.5;		
		MJD0 = Math.floor(MJD);
		ut = (MJD - MJD0)*24.0;		
		t_eph  = (MJD0-51544.5)/36525.0;			
		return  6.697374558 + 1.0027379093*ut + (8640184.812866 + (0.093104 - 0.0000062*t_eph)*t_eph)*t_eph/3600.0;		
	}

function LM_Sidereal_Time (jd, longitude) {
		var GMST = GM_Sidereal_Time(jd);			
		var LMST =  24.0*frac((GMST + longitude/15.0)/24.0);
  return HoursMinutesSeconds(LMST);
	}

function frac(X) {
 X = X - Math.floor(X);
 if (X<0) X = X + 1.0;
 return X;		
}