Nodejs Day Calculate getFistDay()

Method Source Code

Date.prototype.getFistDay = function () {
    var here = new Date(this.getFullYear(), this.getMonth(), 1);
    return here.getDay();
};

Related

1. getDaySimpleSecondsgetDaySimpleSeconds()

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

2. getDaySuffix

   Date.prototype.getDaySuffix =
     function(utc) {
       var n = this.getUTCDate();
       if (n != 11 && (n + '').match(/1$/))
         return 'st';
       else if (n != 12 && (n + '').match(/2$/))
         return 'nd';
       else if (n != 13 && (n + '').match(/3$/))
         return 'rd';
   ...
   

3. getDaysBetweenDates(date2)

   'use strict';
   Date.prototype.getDaysBetweenDates = function (date2) {
     var diff = this.getTime() - new Date(date2).getTime();
     return Math.round(diff / (1000 * 60 * 60 * 24));
   };
   

4. getDaysTillNow(since)

   Date.prototype.getDaysTillNow = function (since) {
       var past = new Date(since.getFullYear(), since.getMonth(), since.getDate());
       var today = new Date(this.getFullYear(), this.getMonth(), this.getDate());
       return (today - past) / (24 * 3600000);
   };
   

5. getDaysUntil(futureDay)

   Date.prototype.getDaysUntil = function(futureDay) {
       var future = new Date(futureDay.getFullYear(), futureDay.getMonth(), futureDay.getDate());
       var today = new Date(this.getFullYear(), this.getMonth(), this.getDate());
       return (future - today) / (24 * 3600000);
   };
   

6. getLocalTotalPassedDays()

   Date.prototype.getLocalTotalPassedDays = function() {
     return Math.floor((+this - this.getTimezoneOffset() * 60 * 1000) / 864e5);
   };
   

7. getNextDay()

   Date.prototype.getNextDay =function() {
      day = this.getDay()+1;  
     return (day);
   };
   var mydate = new Date('2016-01-09');
   document.write(mydate.toDateString()+"<br>");
   document.write(mydate.getNextDay());
   var d = new Date();
   document.write(d.getNextDay());
   ...
   

8. getNumOfDays()

   Date.prototype.getNumOfDays = function()
       "use strict";
       var date = new Date(this.getFullYear(), this.getMonth() + 1, 0);
       return date.getDate();
   };
   

9. getStartOfDay()

   Date.prototype.getStartOfDay = function()
       var date = new Date(this);
       date.setHours(0);
       date.setMinutes(0);
       date.setSeconds(0);
       return date;