Nodejs Month Calculate previous_month()

Method Source Code

Date.prototype.previous_month = function() {
  var day = this.getDate();
  var month = this.getMonth() - 1;
  var year = this.getFullYear();
  if (month < 0) {
    month = 11;//ww w  .j  a v  a 2s  . com
    year--;
  }
  return new Date(year, month, day);
}

Related

1. isSameMonth(d)

   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;
   

2. month()

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

3. 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));
   ...
   

4. 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':
   ...
   

5. monthOfYear()

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

6. subMonths(value)

   Date.prototype.subMonths = function(value) {
     var date = this.getDate();
     this.setMonth(this.getMonth() - value);
     if (this.getDate() < date) {
       this.setDate(0);
     return this;
   };
   

7. toMonthEnd()

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

8. toMonthStart()

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