Nodejs Utililty Methods Time Calculate

var DAY_WIDTH = 100;
var DAY_HEIGHT = 80;
var SIDE_DELTA = 2;
var DAY_HEADING = ["SUN",
                   "MON",
                   "TUE",
                   "WED",
                   "THU",
                   "FRI",
...

Date.prototype.timeToJSON = function() {
  return this.toLocaleTimeString().substring(0,5);
};

Date.prototype.timeToMidnight = function() {
    this.setHours(0);
    this.setMinutes(0);
    this.setMilliseconds(0);
};

function time_between_in_words(from_date, to_date)
  return format_milliseconds(Math.abs(from_date.getTime()-to_date.getTime()));
function time_ago_in_words(date)
  return format_milliseconds(Math.abs(Date.now()-date.getTime()));
function format_milliseconds(milsecs)
...

var chunks = [
  [60 * 60 * 24 * 365, 'year'],
  [60 * 60 * 24 * 30, 'month'],
  [60 * 60 * 24 * 7, 'week'],
  [60 * 60 * 24, 'day'],
  [60 * 60, 'hour'],
  [60, 'minute']
];
Date.prototype.time_since = function() {
...

Date.prototype.timesince = function(now) {
  var chunks = [
    [ 60 * 60 * 24 * 365, 'year', 'years'],
    [ 60 * 60 * 24 * 30, 'month', 'months' ],
    [ 60 * 60 * 24, 'day', 'days' ],
    [ 60 * 60, 'hour', 'hours' ],
    [ 60, 'minute', 'minutes' ]
  ];
  now = now || new Date();
...

Date.prototype.withoutTime = function () {
    var d = new Date(this);
    d.setHours(0, 0, 0, 0);
    return d;

Date.prototype.xsdDateTime = function() {
    var yyyy = this.getFullYear().toString();
    var mm = (this.getMonth()+1).toString(); 
    var dd = this.getDate().toString();
    var hh = this.getHours().toString();
    var min = this.getMinutes().toString();
    var sec = this.getSeconds().toString();
    return yyyy + '-' + (mm[1]?mm:"0"+mm[0]) + '-' + (dd[1]?dd:"0"+dd[0]) + 'T' + (hh[1]?hh:"0"+hh[0]) + ':' + (min[1]?min:"0"+min[0]) + ':' + (sec[1]?sec:"0"+sec[0]); 
  };
...