Nodejs Utililty Methods Day Calculate

this.models = {}
Date.Timecop = function() {
  this.daysOffset = 0
Date.timecop = new Date.Timecop
Date.Timecop.prototype.travelDays = function(newOffset) {
  this.daysOffset = newOffset
Date.Timecop.prototype.now = function() {
...

Date.dayDateFromTime = function(time) {
    var date = new Date(time);
    date.setHours(0, 0, 0, 0);
    return date;
};

Date.prototype.DiffInDays = function (date) {
  if(date instanceof Date && !isNaN(date.getTime())) {
    var cDate = this.getTime();
    var tDate = date.getTime();
    var resultMillis = Math.abs(cDate - tDate);
    var result = resultMillis / 1000 / 60 / 60 / 24;
    return result;
  } else {
    console.error(date, " is not a valid date.")
...

Date.prototype.MaxDayOfDate = function(date) {
    var nowDate = new Date(date.getFullYear(), date.getMonth() + 1, 0);
    var lastDay = nowDate.getDate();
    return lastDay;
};

Date.prototype.countDown = function(withDays){
    addDays = (typeof withDays === 'undefined') ? true : withDays;
  var timeLeft = (this/1000) - ((new Date())/1000)
  var days, hours, minutes, seconds;
    var timeArray = []
    if(addDays){
     days = parseInt(timeLeft/86400)
       timeArray.push(days)
     timeLeft = timeLeft % 86400
...

Date.prototype.dayName = function(language) {
  var dayName = "";
  language = language || 'en';
  switch(language.toLowerCase()) 
    case 'en':
      dayName = ['Sunday','Monday','Tuesday','Wednesday', 'Thursday','Friday','Saturday'];
      break;
    case 'es':
...

Date.dayNames = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
Date.monthNames = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
Date.prototype.dayNames = Date.dayNames;
Date.prototype.monthNames = Date.monthNames;
Date.prototype.getDayName = function() {
  return this.dayNames[this.getDay()];
};
Date.prototype.getDayNameAbbr = function() {
  return this.getDayName().slice(0,4);
...

Date.prototype.getDayFormatted = function() {
    var day = this.getDate();
    return day < 10 ? '0' + day : day; 
};

Date.prototype.getDayNumber = function(){
  var oneDay = 1000*3600*24;
  var d = new Date(+this);
  d.setHours(0,0,0,0);
  var newYears = new Date();
  newYears.setDate(1);
  newYears.setMonth(0);
  newYears.setHours(0,0,0,0);
  var timeDiff = Math.abs(d.getTime() - newYears.getTime());
...

Date.prototype.getDaySeconds = function getDaySeconds() {
  return (this.getUTCHours()* 60 + this.getUTCMinutes())*60 + this.getUTCSeconds() + this.getUTCMilliseconds()/1000;