Nodejs Month Calculate subMonths(value)

Method Source Code

Date.prototype.subMonths = function(value) {
   var date = this.getDate();
   this.setMonth(this.getMonth() - value);

   if (this.getDate() < date) {
      this.setDate(0);//from w  w w . jav  a  2 s  . c om
   }

   return this;
};

Related

1. month()

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

2. monthAbbrev[ "Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec" ];

   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));
   ...
   

3. monthName(language)

   Date.prototype.monthName = function(language) {
     var monthName = "";
     language = language || 'en';
     switch(language.toLowerCase()) 
       case 'en':
         monthName = ['January','February','March','April','May','June','July', 'August','September','October','November','December'];
         break;
       case 'es':
   ...
   

4. monthOfYear()

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

5. previous_month()

   Date.prototype.previous_month = function() {
     var day = this.getDate();
     var month = this.getMonth() - 1;
     var year = this.getFullYear();
     if (month < 0) {
       month = 11;
       year--;
     return new Date(year, month, day);
   ...
   

6. toMonthEnd()

   Date.prototype.toMonthEnd = function () {
       var date = new Date(this);
       date.setMonth(date.getMonth() + 1);
       date.setDate(0);
       return date;
   };
   

7. toMonthStart()

   Date.prototype.toMonthStart = function () {
       var date = new Date(this);
       date.setDate(1);
       return date;
   };