Nodejs Utililty Methods Month Calculate

Date.prototype.getMonthStart = function () {
  return new Date(this.getFullYear(), this.getMonth(), 1);
};

Date.prototype.getShortMonth = function () {
   return ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"][this.getMonth()];
};

Date.prototype.getShortMonthName = function () {
  var monthNames = ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
  ];
  return monthNames[this.getMonth()];
};

var aMonths = [ 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December' ]
var aDays = [ 'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday' ]
Date.prototype.incrementMonth = function ( iIncrementValue )
  this.setMonth(
    this.getMonth() + iIncrementValue
  )
Date.prototype.toDayString = function ()
...

Date.prototype.isAfterMonth = function (d) {
    var tDate = new Date(this.getFullYear(), this.getMonth(), this.getDate());
    var pDate = new Date(d.getFullYear(), d.getMonth(), d.getDate());
    if(tDate.getFullYear() < pDate.getFullYear()) return false;
    if(tDate.getMonth() < pDate.getMonth()) return false;
    return true;

Date.prototype.isBeforeMonth = function (d) {
    var tDate = new Date(this.getFullYear(), this.getMonth(), this.getDate());
    var pDate = new Date(d.getFullYear(), d.getMonth(), d.getDate());
    if(tDate.getFullYear() > pDate.getFullYear()) return false;
    if(tDate.getMonth() > pDate.getMonth()) return false;
    return true;

Date.prototype.isSameMonth = function (d) {
    var tDate = new Date(this.getFullYear(), this.getMonth(), this.getDate());
    var pDate = new Date(d.getFullYear(), d.getMonth(), d.getDate());
    return tDate.getMonth() == pDate.getMonth() 

Date.prototype.isSameMonth = function(d){
    var tDate = new Date(this.getFullYear(), this.getMonth(), this.getDate());
    var pDate = new Date(d.getFullYear(), d.getMonth(), d.getDate());
    if(tDate.getFullYear() != pDate.getFullYear()) return false;
    if(tDate.getMonth() != pDate.getMonth()) return false;
    return true;

Date.prototype.month = function()
  var months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
  return months[this.getMonth()];

Date.prototype.monthAbbrev = [ "Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec" ];
Date.prototype.monthFull = [ "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" ];
Date.prototype.weekAbbrev = [ "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
Date.prototype.weekFull = [ "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
Date.prototype.format = function(format)
  var output = format;
  output = output.replace("uHH",this.getUTCHours().toString().padLeft("0",2));
  output = output.replace("HH",this.getHours().toString().padLeft("0",2));
...