The Sky Of Baronie

Welcome to this site, dedicated to the beauty of the sky of Sardinia...

• Julian Day
• Day of the Week
• Countdown
• Calendar HTML

Calculation of Julian Day at this moment:

<script language="JavaScript" type="text/javascript">
 //<!-- 

    var njd=calcola_jd();  // (1)Calculate J.D. reported at the time of Greenwich in this instant.

    document.write(njd);   // writes the result.

 //-->

</script>

 //The line (1) can be replaced with one of the following functions ...

 var njd=calcola_jdUT0();     // calculates the J.D. for the time 0 (zero) in U.T. today
 var njd=calcola_jda();       // calculates the J.D. for the beginning of this year.
 var njd=calcola_jd_anno(yy); // J.D. for the beginning of the year specified in the parameter (yy).

 var njd=calcola_jddata(dd,mm,yy,hh,mi,se);  // Calculate J.D. for any date.

Listing valid for any date:

<script language="JavaScript" type="text/javascript">
    //<!--

    //calculates the J.D. for the date specified in the variables.

    var dd=23;                     // day.
    var mm=6;                      // month.
    var yy=2011;                   // year.
    var hh=10;                     // hours.
    var mi=20;                     // minutes.
    var se=30.256;                 // seconds (may have decimals).

    var njd=calcola_jddata(dd,mm,yy,hh,mi,se);

    document.write(njd);      // writes the results.

    //-->

</script>

The first seven lines of the listing, can be reduced to a minimum, with the inclusion of the numerical values of the date, directly in the function:

    var njd=calcola_jddata(23,6,2011,10,20,30.256); // Date.

Attention to the comma ( , ) used for the separation of the parameters from the one for decimal numbers ( . ).

Obtain the date of the calendar according to the Julian Day:

<script language="JavaScript" type="text/javascript">
    //<!--

    //Gets the date (dd,mm,yy) known number of Julian Day.

    var njd=2455735.93;           // Enter the number of J.D. date.

    var data=jd_data(njd);        // array dates calendar.

                                      // writes results.

    document.write(data[0]+" | ");    // day on decimals hours.
    document.write(data[1]+" | ");    // month.
    document.write(data[2]+" | ");    // year.
    document.write(data[3]+" | ");    // day of the week in Italian 
    document.write(data[4]+" || ");   // day of the week in English 
    document.write(data[5]+" || ");   // numerical value on day of the week (0,1,2, ..6).

    var day=sc_day(data[0]);   // sc_day divide the day in dd,hh,mm,ss.

    document.write(day);      // day,hours,minutes,seconds


    //-->

</script>

Day of the Week:

In order to calculate in what day of the week a certain date falls on, use this listing…

<script language="JavaScript" type="text/javascript">

    //<!--
    //recovers the day of the week.

    var dd=12;                    // day.
    var mm=10;                    // month.
    var yy=1492;                  // year.
    var hh=2;                     // hours 
    var mi=0;                     // minutes 
    var se=0;                     // seconds

    var  njd=calcola_jddata(dd,mm,yy,hh,mi,se); // J.D. Date

    var data=jd_data(njd);                      // day of the week

    document.write(data[4]);      // day of the week in english (abbreviated).

    // For the 12 October 1492 the result is: "Fr" - which corresponds to Friday.

    //-->

</script>

The number of days elapsed since the beginning of the year.

<script language="JavaScript" type="text/javascript">

    //<!--
    //number of days elapsed since the beginning of the year.


    var     njd=calcola_jd();;      // J.D. today.
    var  njd_ia=calcola_jda(); ;    // J.D. for beginning of the year.

    var num_day=njd-njd_ia;                    // elapsed days.
        num_day=parseInt(num_day);             // remove decimals.

    document.write("Elapsed Days : "+num_day);      // writes the results.


    //-->

</script>

Calculating the Number of Days Between Two Dates:

With a listing similar to the previous one it is possible to obtain the days that passed between any two events; all you have to do is use the function calculate_jddate(dd,mm,yy,hh,mi,se). replacing the two previous ones and inserting the two dates in the parameters…

<script language="JavaScript" type="text/javascript">

    //<!--
    //Obtain the days that passed between two events.


    var     njd=calcola_jddata(23,6,1986,0,0,0);   // Date1: 23-06-1986.
    var  njd_ia=calcola_jddata(23,1,2011,0,0,0);   // Date2: 23-01-2011.

    var num_giorno=njd-njd_ia;                     // the number of elapsed days.
        num_giorno=parseInt(num_giorno);           // delete the decimals.

    document.write("the number of days elapsed: "+num_giorno+"!");      // writes the results.


    //-->

</script>

To estimate the number of days elapsed since the beginning of the year, using the last listing; you must enter 0 in January, instead of January 1: calculate_jddate(0,1,2011,0,0,0), which corresponds to January 0, 2011.

Countdown listing (1):

Using the julian numbering system, it is easy to create a simple Countdown…

<p id="posdata">posizione del countdown</p>   <!-- Position of the date in HTML document  --> 

<script language="JavaScript" type="text/javascript">

    //<!--
    //Countdown (listing 1)

    var  njd_cd=calcola_jddata(23,12,2012,0,0,0); // Countdown date.

    countdown(njd_cd);

      function countdown(njd_cd) { 

          var        njd=calcola_jd();;           // the J.D. today.
          var num_giorno=njd_cd-njd;              // number elapsed days.
              num_giorno=sc_day(num_giorno);      // Date formatting.

          document.getElementById("posdata").innerHTML=(""+num_giorno);

      }

z=setInterval("countdown(njd_cd)",1000);

    //-->

</script>

If you are not satisfied with the type of date format, you can eliminate the function sc_day(...) and “manually” calculate the times.

var dd_dec=Math.abs(num_giorno);                        // absolute value.

var dd=parseInt(dd_dec);                                //     days. 
var hh=parseInt((dd_dec-dd)*24);                        //    hours. 
var mm=parseInt(((dd_dec-dd)*24-hh)*60);                //  minutes. 
var ss=parseInt(((((dd_dec-dd)*24-hh)*60)-mm)*60);      //  seconds. 

Countdown listing (2):

<h2 id="posdata">posizione del countdown</h2>   <!-- Position of the date in HTML document --> 

<script language="JavaScript" type="text/javascript">

    //<!--
    //Countdown (listing 2).

    var  njd_cd=calcola_jddata(23,12,2012,0,0,0); // Countdown date.

    countdown(njd_cd);

      function countdown(njd_cd) { 

          var        njd=calcola_jd();;           // J.D. today.
          var num_giorno=njd_cd-njd;              // elapsed days.

          var dd_dec=Math.abs(num_giorno);                       // absolute value.

          var dd=parseInt(dd_dec);                               //     days. 
          var hh=parseInt((dd_dec-dd)*24);                       //    hours. 
          var mm=parseInt(((dd_dec-dd)*24-hh)*60);               //  minutes. 
          var ss=parseInt(((((dd_dec-dd)*24-hh)*60)-mm)*60);     //  seconds. 

          var date=dd+":"+hh+":"+mm+":"+ss;                      //days+hours+minutes+seconds. 

          document.getElementById("posdata").innerHTML=(""+date);

      }

z=setInterval("countdown(njd_cd)",1000);

    //-->

</script>

//To get the seconds with (2) decimal places, replace the seconds line of (ss), with this::

         var ss=(((((dd_dec-dd)*24-hh)*60)-mm)*60).toFixed(2);  // the seconds with 2 decimals. 

Create a calendar with HTML, JavaScript and AstroJS:

Using the J.D. it is possible to realize a calendar as this.

<script language="JavaScript" type="text/javascript">

  var      dd=new Array("");
  var classed=new Array("");    // CSS Class

  var    data=new Date();       // Date: 
  var      yy=data.getYear();   // recovers the current year
  var      mm=data.getMonth();  // recovers the current month : 0 a 11  
  var     dd0=data.getDate();   // recovers the number of current day from 1 at 31.
           mm=mm+1;             // value of month between 1-12. 

   if (yy<1900) {yy=yy+1900;}   // correction of the year for the browser. 

   var numbers_days=calcola_dd_mese(mm,yy);// calculates the number of day of the month: 28-31

   var njd=calcola_jddata(1,mm,yy,0,0,0);  // julian day of the first day of the month.
   var data_cal=jd_data(njd);
   var aa=data_cal[5];    // check which day of the week falls on the 1st day of the month. 
                          // return a number between 0,....6   0=Sunday  6=Saturday
   var nn_days=40;
   var   nrows=5;         // number of rows

 // if the  first day of the month falls the Friday or Saturday,
 // adds a one row to calendar: rows=6.
 // adds 5 days to nn_giorni=45.

   if (data_cal[5]==6 || data_cal[5]==5 ) {nrows=6; nn_days=45; }

for (c=0; c<nn_days; c++){   dd[c]=""; classed[c]="colore_tabellavv"; }

for(b=1 ; b<numbers_days+1; b++){
   dd[aa+b-1]=b;
   classed[aa+b-1]="colore_tabella";
   if(b==dd0){classed[aa+b-1]="colore_tabellagg";}
   }

 //  Create the table for the calendar

var name_month=rec_month(mm);                   // Recovery of the current month.

document.write("<div id='calendario'>");

document.write("<h3>"+name_month+" "+yy+"<h3>");

document.write("<table width=70%>");

         document.write("   <tr>");
         document.write("     <td width=10% class='colore_tabellaef2'>Sun</td>");
         document.write("     <td width=10% class='colore_tabellaef2'>Mon</td>");
         document.write("     <td width=10% class='colore_tabellaef2'>Tue</td>");
         document.write("     <td width=10% class='colore_tabellaef2'>Wed</td>");
         document.write("     <td width=10% class='colore_tabellaef2'>Thu</td>");
         document.write("     <td width=10% class='colore_tabellaef2'>Fri</td>");
         document.write("     <td width=10% class='colore_tabellaef2'>Sat</td>");
         document.write("   </tr>");
 z=0;

for(a=0; a<nrows; a++) {

         document.write("   <tr>");
         document.write("     <td class='"+classed[z]+  "'>"+dd[z]+"</td>");
         document.write("     <td class='"+classed[z+1]+"'>"+dd[z+1]+"</td>");
         document.write("     <td class='"+classed[z+2]+"'>"+dd[z+2]+"</td>");
         document.write("     <td class='"+classed[z+3]+"'>"+dd[z+3]+"</td>");
         document.write("     <td class='"+classed[z+4]+"'>"+dd[z+4]+"</td>");
         document.write("     <td class='"+classed[z+5]+"'>"+dd[z+5]+"</td>");
         document.write("     <td class='"+classed[z+6]+"'>"+dd[z+6]+"</td>");
         document.write("   </tr>");

 z=z+7;

}
         document.write(" </table>");

document.write("</div>");

//Function for the Recovery of the current month.

function rec_month(mm){


           mm=mm-1;

                  if(mm==0)  {name_month="January"; }
            else  if(mm==1)  {name_month="February"; }
            else  if(mm==2)  {name_month="March"; }
            else  if(mm==3)  {name_month="April"; }
            else  if(mm==4)  {name_month="May"; }
            else  if(mm==5)  {name_month="June"; }
            else  if(mm==6)  {name_month="July"; }
            else  if(mm==7)  {name_month="August"; }
            else  if(mm==8)  {name_month="September"; }
            else  if(mm==9)  {name_month="October"; }
            else  if(mm==10) {name_month="November"; }
            else  if(mm==11) {name_month="December"; }

            return name_month;

}

</script>

CSS Code for the calendar layout:

#calendario{
 background-color: #EEEEEE;
 width: 220px;
 border: 1px solid blue;
 margin: 0px;
 padding:0px;}

table{   width: 100%; margin-bottom: 0px; padding-bottom: 0px;}

h3{  text-align: center; padding: 0px; margin-top: 0px; border-bottom: 0px;
     font-family: Courier New;
     color: #990000;}

#calendario td {
   color: black;
   font-family: Arial;
   font-size: 8pt;
   padding: 2px;
   margin: 2px;
   font-weight: normal;
   }

.colore_tabellaef2{ background-color: gray; border: 1px solid gray;
                    font-family: Arial, Helvetica, sans-serif;
                    font-size: 10pt; }                               /* names of days  */

.colore_tabella   { background-color: #DDDDDD; }                     /* day of month  */
.colore_tabellagg { background-color: #FF0033; font-weight: bold;}   /* day of today  */
.colore_tabellavv { background-color: #EEEEEE; }                     /* empty cells   */