var  sitelon,sitelat,AltitudeLimit,Thedateinquestion, Twilight
var deg_pr_hour=15.04107 ; // for higher accuracy/ iteration
			   // this accounts for the difference between the solar day and the sidereal day
var deg_pr_hour=15.00 ; // for normal accuracy/ no iteration
var deg_pr_hour_15=15 ; //no iteration



function PrintResults(){

var page

//   PrintWindow = window.open("","Print_window","menubar=no,status=yes,toolbar=yes,scrollbars=yes,height=480,width=800");

page='<PRE>\n';
page+='\n';
page+='                             20©06 Jens T. Satre\n';    
page+='                   http://www.satellite-calculations.com\n';


page+='\n';
page+='\n';
page+='\n';
page+=document.Sun.Results.value;
page+='\n';
page+='        Calculated after the method on http://www.stjarnhimlen.se/comp/riset.html\n';
page+='</PRE>\n';

document.write(page);


}



function UpdateAltitude(){

//document.Sun.SelectedAltitudeLimit.value=AltitudeLimit;
}

function init()
{
var justnow
justnow= new Date();
Thedateinquestion = new Date();
Thedateinquestion = justnow;

AltitudeLimit=-0.833;
//window.alert('Alt limit='+document.Sun.Alt.value);

//document.Sun.SelectedAltitudeLimit.value=AltitudeLimit;

document.Sun.Day.value=justnow.getDate();
document.Sun.Month.value=justnow.getMonth()+1;
document.Sun.Year.value=justnow.getFullYear();
}


function OnChangeSelectedAltitudeLimit(){

//document.Sun.Alt.value=document.Sun.SelectedAltitudeLimit.value;

Twilight='Manually selected.';

}

function DateManuallyChanged()
{


Thedateinquestion.setDate(document.Sun.Day.value);
Thedateinquestion.setMonth(document.Sun.Month.value-1);
//document.Sun.Month.value=Thedateinquestion.getMonth()+1;

Thedateinquestion.setFullYear(document.Sun.Year.value);


}


function d_to_date_and_time(d)
{
var today,t
var MinMilli = 1000 * 60;
var HrMilli = MinMilli * 60;
var DyMilli = HrMilli * 24;

today = new Date();

// d+10956= Date() format
//window.alert('d= '+d );

d=d+10956;
d*DyMilli;
today.setTime(d*DyMilli);
//t=((today.getTime()/DyMilli)-10956);
//window.alert('t= '+t );

time_offset=today.getTimezoneOffset()  ;
Hour= today.getUTCHours() ;
Minute=today.getUTCMinutes() ;
Second=today.getUTCSeconds() ;
Month= today.getUTCMonth()+1;
Day= today.getUTCDate() ;
Year= today.getUTCFullYear();


return(today)

}





function Main(){
var Day,Month,Year,Hour,Minute,Second,today,t,d,d_sun_south,d_sun_south_yesterday
var nautical_twilight_start,nautical_twilight_stop
var civil_twilight_start,civil_twilight_stop
var astronomical_twilight_start,astronomical_twilight_stop
var amateur_astronomical_twilight_start,amateur_astronomical_twilight_stop
var sun_rise,sun_set,Daylength_hour,Daylength_minute,Daylength_hour_yesterday,Daylength_minute_yesterday
var Difference,Difference_hour,Difference_minute,DifferenceSign,Difference_seconds
var result_array = new Array( );
var input_array = new Array( );
var astromical,amateur,civil,nautical
var sun_above_userdefined,sun_below_userdefined
var sun_rise_solstice,sun_set_solstice,d_sun_solstice,d_sun_south_solstice
var Daylength_minute_solstice,Daylength_hour_solstice,Difference_hour_solstice,Difference_minute_solstice,Difference_seconds_solstice
var Difference_solstice,DifferenceSign_solstice
var eq_Month,eq_Day,eq_Year,equivalent_day,d_today,d_selected,sun_above_horison,solstice_above_horison




today = new Date();
equivalent_day = new Date();
t=today.getTime();
document.Sun.Results.value='';
time_offset=today.getTimezoneOffset()  ;

Hour= Thedateinquestion.getUTCHours() ;
Minute=Thedateinquestion.getUTCMinutes() ;
Second=Thedateinquestion.getUTCSeconds() ;
Month= Thedateinquestion.getUTCMonth()+1;
Day= Thedateinquestion.getUTCDate() ;
Year= Thedateinquestion.getUTCFullYear();



//window.alert('AltitudeLimit selected= '+AltitudeLimit);

//**** FIND  d_sun_south ******

d=daynumber(Day,Month,Year,12,00,00);

d_today=d;




d=d+(time_offset/(60*24));  // Noon local time
//window.alert('time_offset= '+(time_offset/60));

// Iterates for the Sun in south 
result_array=SunSouth(d);
d_sun_south=result_array[0];

d=d_sun_south;
result_array=SunSouth(d);
d_sun_south=result_array[0];
d=d_sun_south;
result_array=SunSouth(d); 
d_sun_south=result_array[0]; // Sun in south time OK
d_to_date_and_time(d_sun_south);




// Iterates for the Sun in south yesterday
result_array=SunSouth(d-1);
d_sun_south_yesterday=result_array[0];

d=d_sun_south_yesterday;
result_array=SunSouth(d);
d_sun_south_yesterday=result_array[0];
d=d_sun_south_yesterday;
result_array=SunSouth(d); 
d_sun_south_yesterday=result_array[0]; // Sun in south yesterday








document.Sun.Results.value = document.Sun.Results.value+'Suns altitude limit                     :' +AltitudeLimit+'_deg (used for sun rise & set)\n';
document.Sun.Results.value = document.Sun.Results.value+Twilight+'\n';

if (document.Sun.LatDir.value=='North') document.Sun.Results.value = document.Sun.Results.value+'Sun south:   ' +d_to_date_and_time(d_sun_south)+'  Altitude: '+formatvalue(result_array[1],6)+'_deg  Azimuth: 180.0_deg\n';
  else document.Sun.Results.value = document.Sun.Results.value+'Sun north:   ' +d_to_date_and_time(d_sun_south)+'  Altitude: '+formatvalue(result_array[1],6)+'_deg  Azimuth: 0.0_deg\n';

document.Sun.Results.value = document.Sun.Results.value+'*********************************************************************************************\n';


//****Astronomical twilight   OK works
h=-18 ;// degrees
input_array[0]=d_sun_south;
input_array[1]=h;
result_array= CalculateStartStop(d_sun_south,h);

if (result_array[2]==0){
astronomical=1;
astronomical_twilight_stop=result_array[0];
astronomical_twilight_start=result_array[1];



} else astronomical=0;

//****Amateur  Astronomical twilight   OK works
h=-15 ;// degrees
input_array[0]=d_sun_south;
input_array[1]=h;
result_array= CalculateStartStop(d_sun_south,h);

if (result_array[2]==0){
amateur=1;
amateur_astronomical_twilight_stop=result_array[0];
amateur_astronomical_twilight_start=result_array[1];

} else amateur=0;

//****Nautical twilight   OK works
h=-12 ;// degrees
input_array[0]=d_sun_south;
input_array[1]=h;
result_array= CalculateStartStop(d_sun_south,h);

if (result_array[2]==0){
nautical=1;
nautical_twilight_stop=result_array[0];
nautical_twilight_start=result_array[1];

} else nautical=0;


//****Civil twilight   OK works
h=-6 ;// degrees
input_array[0]=d_sun_south;
input_array[1]=h;
result_array= CalculateStartStop(d_sun_south,h);

if (result_array[2]==0){
civil=1;
civil_twilight_stop=result_array[0];
civil_twilight_start=result_array[1];

} else civil=0;


//**** Sunrise & set
h=AltitudeLimit ;// degrees
input_array[0]=d_sun_south;
input_array[1]=h;
result_array= CalculateStartStop(d_sun_south,h);

if (result_array[2]==0){
sun_rise=result_array[0];
sun_set=result_array[1];
sun_above_horison=result_array[2];
}

//**** Sunrise & set yesterday
h=AltitudeLimit ;// degrees
input_array[0]=d_sun_south_yesterday;
input_array[1]=h;
result_array= CalculateStartStop(d_sun_south_yesterday,h);

if (result_array[2]==0){
sun_rise_yesterday=result_array[0];
sun_set_yesterday=result_array[1];
}
Daylength_hour_yesterday=Math.floor((sun_set_yesterday-sun_rise_yesterday)*24);
Daylength_minute_yesterday=Math.floor(((sun_set_yesterday-sun_rise_yesterday)*24-Daylength_hour_yesterday)*60);


Difference= (sun_set-sun_rise) -(sun_set_yesterday  - sun_rise_yesterday);
DifferenceSign='';

if (Difference<0) DifferenceSign='-';
if (Difference>0) DifferenceSign='+';
Difference=Math.abs(Difference);

Difference_hour=Math.floor(Difference*24);

Difference_minute=Math.floor(((Difference*24) -Difference_hour)*60);
Difference_seconds=Math.floor(( ((Difference*24) -Difference_hour)*60 -Difference_minute) *60);  

// calculate daylength for 21 December and 21 June and 
// display difference since last solstice
// equinox = 0 deg. At solstice = 23.45 degs
// find last solstice, calculate daylength, use this as reference
// 


// must find a way of calculating last d_sun_solstice
// 

// if Year

//document.Sun.Day.value=justnow.getDate();
//document.Sun.Month.value=justnow.getMonth()+1;
//document.Sun.Year.value=justnow.getFullYear();

d_selected=daynumber(document.Sun.Day.value*1,document.Sun.Month.value*1,document.Sun.Year.value*1,12,00,00);


//if (document.Sun.LatDir.value=='North') sitelat=document.Sun.Latitude.value
//   else sitelat=-document.Sun.Latitude.value;
//if (document.Sun.LonDir.value=='West') sitelon=- document.Sun.Longitude.value
//   else sitelon=document.Sun.Longitude.value;


// sjekk i stedet mot dag/måned , etter 21.12 , før 21.06

	if (document.Sun.LatDir.value=='North') {

		if (DifferenceSign=="+") {
    
    		if ((document.Sun.Day.value*1>21)&&(document.Sun.Month.value*1==12)) d_sun_solstice=daynumber(21,12,(document.Sun.Year.value*1),12,00,00)
       			else d_sun_solstice=daynumber(21,12,(document.Sun.Year.value*1-1),12,00,00);
    		// unntak når dagen i året er passert 21,12...	
 
   		}
   		else 
   		{
   		//alert('test');
  		// if ((document.Sun.Day.value*1>21)&&(document.Sun.Month.value*1==06)) d_sun_solstice=daynumber(21,06,(document.Sun.Year.value*1),12,00,00)
   		//    else d_sun_solstice=daynumber(21,06,(document.Sun.Year.value*1),12,00,00);
    		// unntak når dagen i året er passert 21,12...	
 
    		d_sun_solstice=daynumber(21,06,(document.Sun.Year.value*1),12,00,00);  // fixed at this time

   		}
	}

	else 
	{
		if (DifferenceSign=="-") {
    
    		if ((document.Sun.Day.value*1>21)&&(document.Sun.Month.value*1==12)) d_sun_solstice=daynumber(21,12,(document.Sun.Year.value*1),12,00,00)
       			else d_sun_solstice=daynumber(21,12,(document.Sun.Year.value*1-1),12,00,00);
    		// unntak når dagen i året er passert 21,12...	
 
   		}
   		else 
   		{
   		//alert('test');
  		// if ((document.Sun.Day.value*1>21)&&(document.Sun.Month.value*1==06)) d_sun_solstice=daynumber(21,06,(document.Sun.Year.value*1),12,00,00)
   		//    else d_sun_solstice=daynumber(21,06,(document.Sun.Year.value*1),12,00,00);
    		// unntak når dagen i året er passert 21,12...	
 
    		d_sun_solstice=daynumber(21,06,(document.Sun.Year.value*1),12,00,00);  // fixed at this time

   		}
	}


// 
// Iterates for sun_south solstice
result_array=SunSouth(d_sun_solstice);
d_sun_south_solstice=result_array[0];

d=d_sun_south_solstice;
result_array=SunSouth(d);
d_sun_south_solstice=result_array[0];
d=d_sun_south_solstice;
result_array=SunSouth(d); 
d_sun_south_solstice=result_array[0]; // Sun in south at selected solstice



h=AltitudeLimit ;// degrees
input_array[0]=d_sun_south_solstice;  // blir feil...
input_array[1]=h;
result_array= CalculateStartStop(d_sun_south_solstice,h);
//alert(d_sun_south_solstice);
solstice_above_horison=result_array[2];

if (result_array[2]==0){ // sun above the limit on parts of the day

sun_rise_solstice=result_array[0];
sun_set_solstice=result_array[1];

Daylength_hour_solstice=Math.floor((sun_set_solstice-sun_rise_solstice)*24);
Daylength_minute_solstice=Math.floor(((sun_set_solstice-sun_rise_solstice)*24-Daylength_hour_solstice)*60);

Difference_solstice= (sun_set-sun_rise) -(sun_set_solstice- sun_rise_solstice);

DifferenceSign_solstice='';

if (Difference_solstice<0) DifferenceSign_solstice='-';
if (Difference_solstice>0) DifferenceSign_solstice='+';
Difference_solstice=Math.abs(Difference_solstice);

Difference_hour_solstice=Math.floor(Difference_solstice*24);

Difference_minute_solstice=Math.floor(((Difference_solstice*24) -Difference_hour_solstice)*60);
Difference_seconds_solstice=Math.floor(( ((Difference_solstice*24) -Difference_hour_solstice)*60 -Difference_minute_solstice) *60);  


}


if (solstice_above_horison==-1) { // always below horizon at solstice



//alert("always below horizon");

Difference_solstice=-(1-(sun_set-sun_rise));
//DifferenceSign_solstice='';
if (Difference_solstice<0) DifferenceSign_solstice='-';
if (Difference_solstice>0) DifferenceSign_solstice='+';
Difference_solstice=Math.abs(Difference_solstice);
Difference_hour_solstice=Math.floor(Difference_solstice*24);
Difference_minute_solstice=Math.floor(((Difference_solstice*24) -Difference_hour_solstice)*60);
Difference_seconds_solstice=Math.floor(( ((Difference_solstice*24) -Difference_hour_solstice)*60 -Difference_minute_solstice) *60);  
Daylength_hour_solstice=24;
Daylength_minute_solstice=0;
sun_rise_solstice=0;
sun_set_solstice=0;


}

if (solstice_above_horison==1) {  // always above horizon at solstice


//alert("always above horizon");

Difference_solstice=(sun_set-sun_rise);  // i.e. 24 hours - daylength
//DifferenceSign_solstice='';
if (Difference_solstice<0) DifferenceSign_solstice='-';
if (Difference_solstice>0) DifferenceSign_solstice='+';
Difference_solstice=Math.abs(Difference_solstice);
Difference_hour_solstice=Math.floor(Difference_solstice*24);
Difference_minute_solstice=Math.floor(((Difference_solstice*24) -Difference_hour_solstice)*60);
Difference_seconds_solstice=Math.floor(( ((Difference_solstice*24) -Difference_hour_solstice)*60 -Difference_minute_solstice) *60);  
Daylength_hour_solstice=0;
Daylength_minute_solstice=0;
sun_rise_solstice=0;
sun_set_solstice=0;


}



/*

Try to calculate the other day of the year with equivalent day length
*/

if (d_selected>d_sun_solstice) 
  	{

	equivalent_day=d_to_date_and_time( (d_sun_solstice-(d_selected-d_sun_solstice)));
	eq_Month= equivalent_day.getUTCMonth()+1;
	if (eq_Month<10) eq_Month='0'+eq_Month;
	eq_Day= equivalent_day.getUTCDate() ;
	if (eq_Day<10) eq_Day='0'+eq_Day;
	eq_Year= equivalent_day.getUTCFullYear();
	}
	else
	{
        //alert('d_selected<d_sun_solstice');
	equivalent_day=d_to_date_and_time( (d_sun_solstice+(d_sun_solstice-d_selected)));
	eq_Month= equivalent_day.getUTCMonth()+1;
	if (eq_Month<10) eq_Month='0'+eq_Month;
	eq_Day= equivalent_day.getUTCDate() ;
	if (eq_Day<10) eq_Day='0'+eq_Day;
	eq_Year= equivalent_day.getUTCFullYear();
	}



if (astronomical==1) document.Sun.Results.value = document.Sun.Results.value+'Astronomical twilight ends              : ' + d_to_date_and_time(astronomical_twilight_stop)+'\n';

if (amateur==1)      document.Sun.Results.value = document.Sun.Results.value+'Amateur astronomical twilight ends      : ' + d_to_date_and_time(amateur_astronomical_twilight_stop)+'\n';

if (nautical==1)  document.Sun.Results.value =    document.Sun.Results.value+'Nautical twilight ends                  : ' + d_to_date_and_time(nautical_twilight_stop)+'\n';


if (civil==1) document.Sun.Results.value =        document.Sun.Results.value+'Civil twilight ends                     : ' + d_to_date_and_time(civil_twilight_stop)+'\n';

if (sun_above_horison==-1) document.Sun.Results.value = document.Sun.Results.value+'Sun always above horizon\n'  
     else  if (sun_above_horison==1) document.Sun.Results.value = document.Sun.Results.value+'Sun always below horizon\n'
       else if (sun_above_horison==0) {
       document.Sun.Results.value = document.Sun.Results.value+'Sun rise                                : ' + d_to_date_and_time(sun_rise)+'\n';
       
       Daylength_hour=Math.floor((sun_set-sun_rise)*24)
       Daylength_minute=Math.floor(((sun_set-sun_rise)*24-Daylength_hour)*60);
      // document.Sun.Results.value = document.Sun.Results.value+'Daylength                               : ' +Daylength_hour+'h '+Daylength_minute+'m'+' Yesterday:'+Daylength_hour_yesterday+'h'+Daylength_minute_yesterday+'m ('+DifferenceSign+''+Difference_minute+'m'+Difference_seconds+'s'+' since yesterday)\n';
      document.Sun.Results.value = document.Sun.Results.value+'Daylength equals '+eq_Day+"/"+eq_Month+"/"+eq_Year+'             : ' +Daylength_hour+'h '+Daylength_minute+'m'+' Yesterday:'+Daylength_hour_yesterday+'h'+Daylength_minute_yesterday+'m ('+DifferenceSign+''+Difference_minute+'m'+Difference_seconds+'s'+' since yesterday)\n';
       document.Sun.Results.value = document.Sun.Results.value+'Daylength                               : ' +Daylength_hour+'h '+Daylength_minute+'m'+' Solstice :'+Daylength_hour_solstice+'h'+Daylength_minute_solstice+'m ('+DifferenceSign_solstice+''+Difference_hour_solstice+'h'+Difference_minute_solstice+'m'+Difference_seconds_solstice+'s'+' since solstice)\n';


       document.Sun.Results.value = document.Sun.Results.value+'Sun set                                 : ' + d_to_date_and_time(sun_set)+'\n'; 

       }




if (civil==1)     document.Sun.Results.value = document.Sun.Results.value+'Civil twilight starts                   : ' + d_to_date_and_time(civil_twilight_start)+'\n';



if (nautical==1)  document.Sun.Results.value = document.Sun.Results.value+'Nautical twilight starts                : ' + d_to_date_and_time(nautical_twilight_start)+'\n';


if (amateur==1)   document.Sun.Results.value = document.Sun.Results.value+'Amateur astronomical twilight starts    : ' + d_to_date_and_time(amateur_astronomical_twilight_start)+'\n';

if (astronomical==1) document.Sun.Results.value = document.Sun.Results.value+'Astronomical twilight start             : ' + d_to_date_and_time(astronomical_twilight_start)+'\n';



//**** User defined rise & set
h=document.Sun.SelectedAltitudeLimit.value ;// degrees
input_array[0]=d_sun_south;
input_array[1]=h;
result_array= CalculateStartStop(d_sun_south,h);

	if (result_array[2]==0){
	sun_above_userdefined=result_array[0];
	sun_below_userdefined=result_array[1];

	}
document.Sun.Results.value = document.Sun.Results.value+'*********************************************************************************************'+'\n'; 

sun_above_userdefined,sun_below_userdefined
if (result_array[2]==-1) document.Sun.Results.value = document.Sun.Results.value+'Sun always above user defined altitude\n'  
     else  if (result_array[2]==1) document.Sun.Results.value = document.Sun.Results.value+'Sun always below user defined altitude\n'
       else if (result_array[2]==0) {
       document.Sun.Results.value = document.Sun.Results.value+'Sun rise above userdefined altitude     : ' + d_to_date_and_time(sun_above_userdefined)+'\n';
       
       Daylength_hour=Math.floor((sun_below_userdefined-sun_above_userdefined)*24)
       Daylength_minute=Math.floor(((sun_below_userdefined-sun_above_userdefined)*24-Daylength_hour)*60);
      

       document.Sun.Results.value = document.Sun.Results.value+'Length above user defined altitude      : ' +Daylength_hour+'h '+Daylength_minute+'m\n';
       document.Sun.Results.value = document.Sun.Results.value+'Sun sets below user defined altitude    : ' + d_to_date_and_time(sun_below_userdefined)+'\n'; 
       
       }

document.Sun.Results.value = document.Sun.Results.value+'*********************************************************************************************'+'\n'; 


 


}


function printresult(){
var listing


listing="<html>"
listing+="<head>"
listing+="<meta http-equiv=Content-Type>"

listing+="<meta name=GENERATOR content=Microsoft FrontPage 4.0>"
listing+="<title>Sun azimuth ~ Satellite Longitude</title>"
listing+="</head>"
listing+="<FONT SIZE=1>"
listing+="<body>"
listing+="<center><font size=+7 face=Arial>"+UTCDateString+"</font></center>"
listing+="<center><font size=+7 face=Arial>"+LTDateString+"</font></center>"
listing+="<br>"
listing+="<br>"
listing+="<center><font size=+7 face=Arial>Satellite Position:"+document.Output.Satpos.value+"</font></center>"
listing+="<br>"
listing+="<center><font size=+7 face=Arial>Sun Azimuth:"+document.Output.SunAzimuth.value+"</font></center>"
listing+="<center><font size=+7 face=Arial>Satellite Elevation:"+document.Output.Satel.value+"</font></center>"
listing+="<br>"
listing+="<center><font size=+7 face=Arial>Sun Elevation:"+document.Output.SunAltitude.value+"</font></center>"
listing+="<br>"
listing+="<center><font size=+7 face=Arial>|Satellite Elevation-Sun Elevation|:"+document.Output.Offaxis.value+"</font></center>"
listing+="</html>"
PrintWindow=window.open("","Print_window")
//PrintWindow =window.open("","Print_window","menubar=yes,status=yes,toolbar=yes,scrollbars=yes"); //height=800,width=1000
PrintWindow.oldWindow = top
//PrintWindow.document.write(document.Output.Satpos.value) 
PrintWindow.document.write(listing)  
PrintWindow.document.close()


}


function CalculateStartStop(d_sun_south,h)
{
var UT_Sun_in_south,today,time_offset,Day,Month,Year,Hour,Minute,Second,today,d,d_sunrise,d_sunset,t,above

//  d = noon local time
var result_array = new Array();
var CosLHA
var return_array = new Array( );
//var deg_pr_hour=15.0;

above=0;

var inputvalues = new Array( );



CosLHA=SunRiseLHA(d_sun_south,h);




if (CosLHA<-1) above=-1
  else if  (CosLHA>1) above=1
    else
    {
    above=0;
    d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sun_south,h)))/deg_pr_hour)/24);

    //window.alert('First d_sunrise='+d_sunrise);  // OK




    // Sjekk første LHA for midnattsol eller mørketid




	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);

	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	d_sunrise =d_sun_south-((Deg(Math.acos(SunRiseLHA(d_sunrise,h)))/deg_pr_hour)/24);
	//window.alert('Second d_sunrise='+d_sunrise);  // OK


  	// OK
	//document.Sun.Results.value = document.Sun.Results.value+'Sun rise  :   ' +d_to_date_and_time(d_sunrise)+' (above defined altitude limit)\n';
	}

if (CosLHA<-1) above=-1
  else if  (CosLHA>1) above=1
    else
    {
     above=0;
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sun_south,h)))/deg_pr_hour)/24);

	//window.alert('First d_sunrise='+d_sunrise);  // OK


	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	d_sunset =d_sun_south+((Deg(Math.acos(SunRiseLHA(d_sunset,h)))/deg_pr_hour)/24);
	//window.alert('Second d_sunrise='+d_sunrise);  // OK



     //  document.Sun.Results.value = document.Sun.Results.value+'Sun set   :   ' +d_to_date_and_time(d_sunset)+' (below defined altitude limit)\n';
	
      // Daylength_hour=Math.floor((d_sunset-d_sunrise)*24)
      // Daylength_minute=Math.floor(((d_sunset-d_sunrise)*24-Daylength_hour)*60);
     //  document.Sun.Results.value = document.Sun.Results.value+'Length above altitude limit: ' +Daylength_hour+'h '+Daylength_minute+'m\n';

       }



return_array[0]=d_sunrise;
return_array[1]=d_sunset;
return_array[2]=above;
//return_array[2]=0;


return(return_array);
}




function SunSouth(d)
{


var SunSouth,HourAngle,SIDEREALTIME,SatAz,SunSat,Tst,SatelliteAzimuth,pi,NewRA
var w,a,e,M,L,oblecl,E,x,y,r,v,sunlon,z,xequat,yequat,zequat,RA,Decl,GMST0,UT,SIDTIME,HA
var CosLHA,h,UT_SunRise,UT_SunSet,d_SUNRISE,Elevation
pi=Math.PI;

var return_array = new Array( );



//*********CALCULATE SUN DATA *********************

// d kommer ikke fram

w=282.9404 + 4.70935E-5 * d ;   //OK
a=1;
e= 0.016709 - 1.151E-9 *d ;
M= 356.0470 + 0.9856002585 * d;
oblecl=23.4393 -3.563E-7 * d ;
L=w+Rev(M);

L=Rev(L);

E=M+ (180/pi)*e*Math.sin(Radians(M))*(  1+e * Math.cos(Radians(M))    );
E=Rev(E);  // OK
x= Math.cos(Radians(E)) -e ;
y= Math.sin(Radians(Rev(E)))*Math.sqrt(1-e*e);
r=Math.sqrt(x*x+y*y);
v=Deg(Math.atan2(y,x));
sunlon=Rev(v+w);

x=r*Math.cos(Radians(sunlon));
y=r*Math.sin(Radians(sunlon));
z=0;

xequat=x;
yequat=y*Math.cos(Radians(oblecl)) +z*Math.sin(Radians(oblecl));
zequat=y*Math.sin(Radians(oblecl)) +z*Math.cos(Radians(oblecl));

RA=Rev(Deg(Math.atan2(yequat,xequat)));   // OK
//window.alert('RA='+RA);
Decl=Deg(Math.atan2(zequat,Math.sqrt(xequat*xequat + yequat*yequat )  ));  // OK
//window.alert('Decl='+Decl);
GMST0=(L+180);

//*********CALCULATE SUNRISE *********************

UT_Sun_in_south=Rev(RA-GMST0-sitelon)/deg_pr_hour_15;  // is ok -time when sun=south

d_sunsouth=(Math.floor(d)+(UT_Sun_in_south/24));

Elevation = Deg(Math.asin(  Math.sin(Radians(sitelat))*Math.sin(Math.atan2(zequat,Math.sqrt(xequat*xequat + yequat*yequat )  ))  +   Math.cos(Radians(sitelat)) *Math.cos(Math.atan2(zequat,Math.sqrt(xequat*xequat + yequat*yequat )  ))  )          );

//document.Sun.Results.value= formatvalue(Elevation,6)+'_deg\n';

return_array[0]=d_sunsouth;
return_array[1]=Elevation;

return(return_array)  // OK


}






function SunRiseLHA(d,h_limit)
{

var SunSouth,HourAngle,SIDEREALTIME,SatAz,SunSat,Tst,SatelliteAzimuth,pi,NewRA
var w,a,e,M,L,oblecl,E,x,y,r,v,sunlon,z,xequat,yequat,zequat,RA,Decl,GMST0,UT,SIDTIME,HA
var CosLHA,h,UT_SunRise,UT_SunSet,d_SUNRISE;
pi=Math.PI;


//*********CALCULATE SUN DATA *********************

h=h_limit;



w=282.9404 + 4.70935E-5 * d ;   //OK
a=1;
e= 0.016709 - 1.151E-9 *d ;
M= 356.0470 + 0.9856002585 * d;
oblecl=23.4393 -3.563E-7 * d ;
L=w+Rev(M);

L=Rev(L);

E=M+ (180/pi)*e*Math.sin(Radians(M))*(  1+e * Math.cos(Radians(M))    );
E=Rev(E);  // OK
x= Math.cos(Radians(E)) -e ;
y= Math.sin(Radians(Rev(E)))*Math.sqrt(1-e*e);
r=Math.sqrt(x*x+y*y);
v=Deg(Math.atan2(y,x));
sunlon=Rev(v+w);

x=r*Math.cos(Radians(sunlon));
y=r*Math.sin(Radians(sunlon));
z=0;

xequat=x;
yequat=y*Math.cos(Radians(oblecl)) +z*Math.sin(Radians(oblecl));
zequat=y*Math.sin(Radians(oblecl)) +z*Math.cos(Radians(oblecl));

RA=Rev(Deg(Math.atan2(yequat,xequat)));   // OK
//window.alert('RA='+RA);
Decl=Deg(Math.atan2(zequat,Math.sqrt(xequat*xequat + yequat*yequat )  ));  // OK
//window.alert('Decl='+Decl);
GMST0=(L+180);

//*********CALCULATE SUNRISE *********************

UT_Sun_in_south=Rev(RA-GMST0-sitelon)/deg_pr_hour_15;  // is ok -time when sun=south

CosLHA=   ( Math.sin(Radians(h)) - (Math.sin(Radians(sitelat))*Math.sin(Radians(Decl))    ) )/(Math.cos(Radians(sitelat))*Math.cos(Radians(Decl))   );

//document.Sun.Results.value = document.Sun.Results.value+'CosLHA   :   ' +CosLHA+'\n';


//*****  Return  SunRise d ,makes it possible to iterate in next round  

UT_SunRise=(Rev((RA-GMST0-sitelon))/deg_pr_hour)-   (Deg(Math.acos(( Math.sin(Radians(h)) - (Math.sin(Radians(sitelat))*Math.sin(Radians(Decl))    ) )/(Math.cos(Radians(sitelat))*Math.cos(Radians(Decl))   )))/deg_pr_hour);
UT_SunSet=Rev((RA-GMST0-sitelon)+Deg(Math.acos(CosLHA)))/deg_pr_hour;
//window.alert('UT_SunRise='+UT_SunRise);  // OK




//window.alert('UT_SunSet='+UT_SunSet);  // OK
d_SUNRISE=(Math.floor(d)+(UT_SunRise/24));

return(CosLHA)

}





function Rev(number)
{
var x
x= number -Math.floor(number/360.0)*360 ;
return(x)
}

function Radians(number)
{

var rad

rad=number*Math.PI/180; 
return(rad)

}

function Deg(number)
{

var rad

rad=number*180/Math.PI; 
return(rad)

}

function daynumber(Day,Month,Year,Hour,Minute,Second)
{

//window.alert(Day+" "+Month+" "+Year+" "+Hour+" "+Minute+" "+Second);


d=367*Year - Div(  (7*(Year+(Div((Month+9),12)))),4 ) + Div((275*Month),9) + Day - 730530 
// d is correct
//window.alert(d);
d=d+ Hour/24 + Minute/(60*24) + Second/(24*60*60)   // OK



return(d)

}


function Div(a,b)
{
return((a-a%b)/b)  //OK
}




function showcredit()
{

var credit
credit=   "Script programmed by Jens T.Saetre   04012004"
credit+="\n02012004 Started programming"
credit+="\n04012004 First uploaded"
credit+="\n04012004 Added user date input(default set to computer date)"
credit+="\n05012004 Calculate length of the day between sunrise & sunset"
credit+="\n11012004 Calculate altitude at sun south or north for southern hemisphere"
credit+="\n18012004 Added manual altitude limit input and better description of the limits"
credit+="\n01022004 Calculate rise,set and twilight in one operation"
credit+="\n03022004 Added button for printable display of results"
credit+="\n01012006 Added daylength difference from last solstice"
credit+="\n01022006 Automatic selection of winter & summer solstice"
credit+="\n11022006 Automatic selection of solstice for any year"
credit+="\n11022006 Calculation of the other day of the year which has got equal daylength or sun altitude"
credit+="\n17022006 Corrected bug in rise&set times for high latitudes"
credit+="\n17022006 Corrected bug in daylength at solstice and daylength difference since solstice"
window.alert(credit);

//var theResponse = window.prompt("Welcome?","Enter your name here.");
}


function ReadCookie()
{
var CookieValue
CookieValue= document.cookie;
if (CookieValue == null) 
{
document.Sun.Location.selectedIndex=1074 // Set default groundstation
}
else
{
var tabell=new Array();
tabell = CookieValue.split(":") ;
document.Sun.Location.selectedIndex=tabell[4] ;// Set default groundstation

//window.alert(tabell[4]+" Readcookie");
}




}  // end readcookie  - works !!!

function Calculate()
{
//document.sun.UTHour.value=10;
}


function SetCookie()
{
var CookieValue
var expires=";expires=Tue, 10 Jul 2040 23:59:59 UTC;" 
CookieValue=document.cookie;
if (CookieValue == null) 
{
var alrt="Error in CookieValue"
alrt+="\nUse Antenna Look Angles calculator to cure the problem";  
window.alert(alrt);
}
else
{
var tabell=new Array();
tabell = CookieValue.split(":") ;
tabell[4]=document.Sun.Location.selectedIndex ;// Set default groundstation

CookieValue="";
document.cookie="";
CookieValue=tabell[0]+":"+tabell[1]+":"+tabell[2]+":"+tabell[3]+":"+tabell[4]+":"+tabell[5]+":"+tabell[6]+":"+tabell[7]+":"+tabell[8]+":"+tabell[9]+":"+tabell[10]+":"+expires;
//window.alert(tabell[4]+" Setcookie");
//window.alert(CookieValue);
document.cookie=CookieValue ;
}

}  // end SetCookie  - works !!!



function SetLocation()

{


   var Location=Array();
   var Longitude=Array();
   var Latitude= Array();
   var LatDeg,LatMin,LatSec,LonDeg,LonMin,LonSec
   var s = document.Sun.Location.value ;
   // Split at each space character.
   Location= s.split(",");   // split into two 
   Latitude=Location[0].split(":");// split into degrees and North/South
   Longitude=Location[1].split(":");// split into degrees and East/West
 //  window.prompt(Longitude[1],"Enter your name here."); 

document.Sun.Latitude.value= Latitude[0];    // Latitude
document.Sun.Longitude.value= Longitude[0];  // Longitude
document.Sun.LatDir.value = Latitude[1];  // Latitude direction
document.Sun.LonDir.value =Longitude[1]; //Longitude direction


document.Sun.LatHour.value=formatvalue( Math.floor(Latitude[0]),2);

LatMin=Math.floor((Latitude[0]-  Math.floor(Latitude[0]))*60); 

LatSec=Math.floor(   ((Latitude[0]-  Math.floor(Latitude[0]))*60  - LatMin)*60 );

document.Sun.LatMin.value=formatvalue(LatMin ,2);
document.Sun.LatSec.value=formatvalue(LatSec ,2);

document.Sun.LonHour.value=formatvalue( Math.floor(Longitude[0]),2);
LonMin=Math.floor((Longitude[0]-  Math.floor(Longitude[0]))*60); 
LonSec=Math.floor(   ((Longitude[0]-  Math.floor(Longitude[0]))*60  - LonMin)*60 );
document.Sun.LonMin.value=formatvalue(LonMin ,2);
document.Sun.LonSec.value=formatvalue(LonSec ,2);


if (document.Sun.LatDir.value=='North') sitelat=document.Sun.Latitude.value
   else sitelat=-document.Sun.Latitude.value;
if (document.Sun.LonDir.value=='West') sitelon=- document.Sun.Longitude.value
   else sitelon=document.Sun.Longitude.value;




}


function formatvalue(input, rsize) // Desimal avrunding
  {
   var invalid = "**************************";
   var nines = "999999999999999999999999";
   var strin = "" + input;
   var fltin = parseFloat(strin);
   if (strin.length <= rsize) return strin;
   if (strin.indexOf("e") != -1 ||
       fltin > parseFloat(nines.substring(0,rsize)+".4"))
      return invalid.substring(0, rsize);
   var rounded = "" + (fltin + (fltin - parseFloat(strin.substring(0, rsize))));
   return rounded.substring(0, rsize);
}

function UpdateCoordinates()
{
var LatDeg,LatMin,LatSec,LonDeg,LonMin,LonSec
LatDeg=1*document.Sun.LatHour.value;
LatMin=1*document.Sun.LatMin.value;
LatSec=1*document.Sun.LatSec.value;
LonDeg=1*document.Sun.LonHour.value;  
LonMin=1*document.Sun.LonMin.value;
LonSec=1*document.Sun.LonSec.value;
document.Sun.Latitude.value=formatvalue((LatDeg + (LatMin/60) + (LatSec/3600)),5) ;     // Latitude
document.Sun.Longitude.value=formatvalue( (LonDeg+ (LonMin/60) + (LonSec/3600)),5);     // Longitude


if (document.Sun.LatDir.value=='North') sitelat=document.Sun.Latitude.value
   else sitelat=-document.Sun.Latitude.value;
if (document.Sun.LonDir.value=='West') sitelon=- document.Sun.Longitude.value
   else sitelon=document.Sun.Longitude.value;


}



function Convert_to_deg_min_sec(){

   var Latitude,Longitude,LatDeg,LatMin,LatSec,LonDeg,LonMin,LonSec
  


Latitude=document.Sun.Latitude.value    // Latitude
Longitude=document.Sun.Longitude.value // Longitude



document.Sun.LatHour.value=formatvalue( Math.floor(Latitude),2);
LatMin=Math.floor((Latitude-  Math.floor(Latitude))*60); 

LatSec=Math.floor(   ((Latitude-  Math.floor(Latitude))*60  - LatMin)*60 );

document.Sun.LatMin.value=formatvalue(LatMin ,2);
document.Sun.LatSec.value=formatvalue(LatSec ,2);

document.Sun.LonHour.value=formatvalue( Math.floor(Longitude),2);
LonMin=Math.floor((Longitude-  Math.floor(Longitude))*60); 
LonSec=Math.floor(   ((Longitude-  Math.floor(Longitude))*60  - LonMin)*60 );
document.Sun.LonMin.value=formatvalue(LonMin ,2);
document.Sun.LonSec.value=formatvalue(LonSec ,2);

if (document.Sun.LatDir.value=='North') sitelat=document.Sun.Latitude.value
   else sitelat=-document.Sun.Latitude.value;
if (document.Sun.LonDir.value=='West') sitelon=- document.Sun.Longitude.value
   else sitelon=document.Sun.Longitude.value;

}

function LatLon()
{
if (document.Sun.LatDir.value=='North') sitelat=document.Sun.Latitude.value
   else sitelat=-document.Sun.Latitude.value;
if (document.Sun.LonDir.value=='West') sitelon=- document.Sun.Longitude.value
   else sitelon=document.Sun.Longitude.value;

}