Nodejs Day Calculate subDays(value)

Method Source Code

Date.parseDate = function (date, format) {
  if (format === undefined)
    format = 'Y-mm-dd';
  return new Date(moment(date, format).valueOf());
};

Date.prototype.subDays = function (value) {
  this.setDate(this.getDate() - value);//from   ww w  .  jav  a  2  s .c om
  return this;
};

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

Date.prototype.subWeeks = function (value) {
  this.subDays(value * 7);
  return this;
};

Date.prototype.subYears = function (value) {
  var month = this.getMonth();
  this.setFullYear(this.getFullYear() - value);
  if (month < this.getMonth()) {
    this.setDate(0);
  }
  return this;
};

Date.prototype.format = function (format) {
  if (format === undefined)
    return this.toString();
  return moment(this).format(format);
};

Related

1. past(pattern,pastDays)

   Date.prototype.past = function(pattern,pastDays){
       var pastday = new Date((this - 0) - 1000*60*60*24*pastDays);
       var pattern = pattern;    
       var dateObj = {
           "Y" : pastday.getFullYear(),
           "M" : pastday.getMonth()+1,
           "D" : pastday.getDate(),
           "h" : pastday.getHours(),
           "m" : pastday.getMinutes(),
   ...
   

2. relativeDays()

   Date.prototype.relativeDays = function() {
     var now = new Date();
     var interval = now.getTime() - this.getTime();
     interval = Math.floor(interval / (1000 * 60 * 60 * 24));
     return interval;
   };
   

3. sGetDay()

   var weekdays = ["monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday"];
   Date.prototype.sGetDay = function() {
     return (this.getDay() + 6) %7;
   var d = new Date();
   var today = weekdays[d.sGetDay()];
   

4. setToMondayMidnight()

   Date.prototype.setToMondayMidnight = function() {
       var weekDay = this.getDay();
       if (weekDay === 0) { 
           weekDay = 7;
       this.setDate(this.getDate() - weekDay + 1);
       this.timeToMidnight();
   };
   

5. shiftDays(days)

   Date.prototype.shiftDays = function(days){    
     days = parseInt(days, 10);
     this.setDate(this.getDate() + days);
     return this;
   $date = new Date(2014, 9, 16,0,1);
   $date.shiftDays(1);
   console.log($date-"");
   $date.shiftDays(1);
   ...
   

6. subDays(value)

   Date.prototype.subDays = function(value) {
     this.setDate(this.getDate() - value);
     return this;
   };
   

7. subtract(days)

   const times = [1000, 10000, 100000, 1000000, 5000000];
   let x = 0;
   Date.prototype.subtract = function(days) {
     return new Date(this.setDate(this.getDate() - days));
   for(i in times) {
     console.time('monkeypatch ' + times[i]);
     while (x < times[i]) {
       x++;
   ...
   

8. subtractDays(days)

   Date.prototype.subtractDays=function(days){
       if (arguments.length===1){
           if (typeof days !== 'number') return;
           this.setDate(this.getDate() - days);
           return this;
       return this;
   

9. yestoday(pattern)

   Date.prototype.yestoday = function(pattern){
       return this.past(pattern,1);
   };