Nodejs Utililty Methods Date Get

Date.prototype.getSimpleMilliseconds = function getSimpleMilliseconds() {
  return (this.getDaySeconds()/ (24*60*60) * (10*100*100)) - this.getDaySimpleSeconds();

Date.prototype.getSimpleSeconds = function getSimpleSeconds() {
  var ss_ofs = this.getDaySimpleSeconds();
  var sm_ofs = Math.floor(ss_ofs/100);
  var sh_ofs = Math.floor(sm_ofs/100);
  return ss_ofs - sm_ofs*100;

Date.prototype.getStDate=function(strDate) {
    var date = eval('new Date(' + strDate.replace(/\d+(?=-[^-]+$)/,
        function (a) { return parseInt(a, 10) - 1; }).match(/\d+/g) + ')');
    return date;
};

Date.prototype.getSuffix = function () {
    switch (this.getDate()) {
        case 1:
        case 21:
        case 31:
            return "st";
        case 2:
        case 22:
            return "nd";
...

Date.prototype.getW3CDTF = function() {
    var year = this.getFullYear();
    var mon  = this.getMonth()+1;
    var day  = this.getDate();
    var hour = this.getHours();
    var min  = this.getMinutes();
    var sec  = this.getSeconds();
    if ( mon  < 10 ) mon  = "0"+mon;
    if ( day  < 10 ) day  = "0"+day;
...

Date.prototype.getYmd = function(){
   return this.getFullYear() + '-' + (this.getMonth() < 10 ? '0' : '') + this.getMonth() + '-' + (this.getDay() < 10 ? '0': '') + this.getDay();