Javascript Date functions: 1. Get AM/PM Hours 2. Get current day number of current year 3. Get current date. format: yyyy-mm-dd

getHoursAMPM

/* 
   1.
*/

Date.prototype.getHoursAMPM = function() {
    var date = new Date();
	  var hours = date.getHours();	 
	  hours = hours % 12;
	  hours = hours ? hours : 12; 
	  return hours;
}

/* usage */
var date = new Date();

var x = date.getHoursAMPM()

/* 
    if the time is 5:00 PM 
    x = 5
*/


/* 
   2.
*/
Date.prototype.getDOY = function() {
    var onejan = new Date(this.getFullYear(),0,1);
    return Math.ceil((this - onejan) / 86400000);
}


/* usage */
var date = new Date();

var x = date.getDOY()

/* 
    if the current date is July 15, 2013
    x = 206
*/





/* 
   3.
*/
Date.prototype.currentIsoDate = function() {
      var currentDate = new Date()
      var day = currentDate.getDate()
      var month = currentDate.getMonth() + 1
      var year = currentDate.getFullYear()
	  return year+'-'+month+'-'+day;
}
 
/* usage */
var date = new Date();
 
var x = date.currentIsoDate()