Nodejs Utililty Methods Time Calculate

Date.prototype.getFullDateTime = function() {
    return this.getFullYear()+'-'+this.getMonthFormatted()+'-'+this.getDayFormatted()+' '+this.getHoursFormatted()+':'+this.getMinutesFormatted()+':'+this.getSecondsFormatted();

Date.prototype.getNumberTime = function() {
  var hour = this.getHours();  
  if (this.getMinutes().length == 1)
    var min = "0" + this.getMinutes();
  else{var min = this.getMinutes();}
  var secs = this.getSeconds();  
  return hour +":"+ min +":"+ secs;

Date.prototype.getPrettyDateTime = function () {
  var month = this.getMonth() + 1;
  var day = (this.getDate() < 10) ? "0" + this.getDate() : this.getDate();
  return month + "/" + day + "/" + this.getFullYear() + " " + this.getPrettyTime();
};

Date.prototype.getPrettyTime = function () {
  var minutes = (this.getMinutes() < 10) ? "0" + this.getMinutes() : this.getMinutes();
  var hours = this.getHours();
  var ampm = "AM";
  if (hours > 12) {
    ampm = "PM";
    hours -= 12;
  } else if (hours == 12) {
    ampm = "PM";
...

Date.prototype.getTimeAmPm = function () {
  let hours = this.getHours();
  let minutes = this.getMinutes();
  let ampm = hours >= 12 ? 'pm' : 'am';
  hours = hours % 12;
  hours = hours ? hours : 12; 
  minutes = minutes < 10 ? '0' + minutes : minutes;
  let strTime = hours + ':' + minutes + '' + ampm;
  return strTime;
...

Date.prototype.getTimeShift = function() {
    return this.getTimezoneOffset() < this.stdTimezoneOffset()?3:2;
};

getQueryString = function (field, url) {
    var href = url || window.location.href;
    var reg = new RegExp('[?&]' + field + '=([^&#]*)', 'i');
    var string = reg.exec(href);
    return string ? string[1] : null;
};
Date.prototype.getUnixTime = function () {
    return this.getTime() / 1000 | 0
};
...

Date.prototype.halfHoursUntil = function(otherTime) {
  var hour = new Date(this);
  var numberOfHalfHours = 0;
  while (hour < otherTime) {
    numberOfHalfHours++;
    hour.addHalfHour();
  return numberOfHalfHours;
};
...

Date.prototype.onlyTime = function () {
  return this.toTimeString().split(" ")[0];
};

Date.prototype.p8DeDate = function(time) {
  var d = this;
  function pad(n) {
    return n < 10 ? '0' + n : n;
  function pad3(n) {
    if(n < 10) {
       return '00' + n;
    } else if(n < 100) {
...