Nodejs Month Calculate getLastDayOfMonth()

Method Source Code

Date.prototype.getLastDayOfMonth = function () {
    var day = (this.getDay() + (Date.daysInMonth[this.getMonth()] - this.getDate())) % 7;
    return (day < 0) ? (day + 7) : day;
}

Related

1. end_of_month()

   Date.prototype.end_of_month = function() {
     var month = this.getMonth() + 1;
     var year = this.getFullYear();
     if (month > 11) {
       month = 0;
       year++;
     return new Date(year, month, 0);
   

2. getAbbrMonth()

   Date.prototype.getAbbrMonth = function() {
     switch(this.getMonth()) {
       case 0: return 'Jan';
       case 1: return 'Feb';
       case 2: return 'March';
       case 3: return 'Apr';
       case 4: return 'May';
       case 5: return 'Jun';
       case 6: return 'July';
   ...
   

3. getCurrentMonthDays()

   Date.prototype.getCurrentMonthDays = function(){
           var thisTime = this.getTime();
           if(this.getMonth() == 11){
               this.setYear(this.getYear()+1);
               this.setMonth(0);
           else{
               this.setMonth(this.getMonth()+1);
           var currentDays = parseInt((this.getTime()-thisTime)/1000/60/60/24);
           this.setTime(thisTime);
           return currentDays; 
   

4. getFirstDayOfMonth()

   Date.prototype.getFirstDayOfMonth = function () {
       var day = (this.getDay() - (this.getDate() - 1)) % 7;
       return (day < 0) ? (day + 7) : day;
   

5. getLastDateInMonth(months)

   Date.prototype.getLastDateInMonth = function (months){
     months = parseInt(months);
     return new Date(this.getFullYear(), this.getMonth() + (months || 0) + 1, 0);
   

6. getMonth2()

   Date.prototype.getMonth2 = function () {
      var month = this.getMonth() + 1;
      return (month < 10 ? '0' : '') + month;
   };
   

7. getMonthEnd()

   Date.prototype.getMonthEnd = function () {
     return new Date(this.getFullYear(), this.getMonth() + 1, 0);
   };
   

8. getMonthStart()

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

9. getShortMonth()

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