Nodejs Week Get getWeek()

Method Source Code

// This script is released to the public domain and may be used, modified and
// distributed without restrictions. Attribution not necessary but
// appreciated.// w ww  .  jav a2s  .c o m
// Source: http://weeknumber.net/how-to/javascript 

// Returns the ISO week of the date.
Date.prototype.getWeek = function() {
   var date = new Date(this.getTime());
   date.setHours(0, 0, 0, 0);
   // Thursday in current week decides the year.
   date.setDate(date.getDate() + 3 - (date.getDay() + 6) % 7);
   // January 4 is always in week 1.
   var week1 = new Date(date.getFullYear(), 0, 4);
   // Adjust to Thursday in week 1 and count number of weeks from date to week1.
   return 1 + Math.round(((date.getTime() - week1.getTime()) / 86400000 - 3 + (week1.getDay() + 6) % 7) / 7);
}

// Returns the four-digit year
// corresponding to the ISO week of the
// date.
Date.prototype.getWeekYear = function() {
   var date = new Date(this.getTime());
   date.setDate(date.getDate() + 3 - (date.getDay() + 6) % 7); 
   return date.getFullYear();
}

Related

1. getWeek()

   Date.prototype.getWeek = function() {
     var onejan = new Date(this.getFullYear(),0,1);
     var today = new Date(this.getFullYear(),this.getMonth(),this.getDate());
     var dayOfYear = ((today - onejan + 86400000)/86400000);
     return Math.ceil(dayOfYear/7)
   };
   var today = new Date();
   var currentWeekNumber = today.getWeek();
   console.log(currentWeekNumber);
   ...
   

2. getWeek()

   Date.prototype.getWeek = function() {
     var date = new Date(this.getTime());
      date.setHours(0, 0, 0, 0);
     date.setDate(date.getDate() + 3 - (date.getDay() + 6) % 7);
     var week1 = new Date(date.getFullYear(), 0, 4);
     return 1 + Math.round(((date.getTime() - week1.getTime()) / 86400000
                           - 3 + (week1.getDay() + 6) % 7) / 7);
   

3. getWeek()

   Date.prototype.getWeek = function () {
       var onejan = new Date(this.getFullYear(), 0, 1);
       return Math.ceil((((this - onejan) / 86400000) + onejan.getDay() + 1) / 7);
   function sumArr(arr) {
       return arr.reduce(function (a, b) { return a + b; }, 0);
   function formatTime(val) {
       var sec_num = parseInt(val, 10); 
   ...
   

4. getWeek()

   Date.prototype.getWeek = function(){
       var day_miliseconds = 86400000,
           onejan = new Date(this.getFullYear(),0,1,0,0,0),
           onejan_day = (onejan.getDay()==0) ? 7 : onejan.getDay(),
           days_for_next_monday = (8-onejan_day),
           onejan_next_monday_time = onejan.getTime() + (days_for_next_monday * day_miliseconds),
           first_monday_year_time = (onejan_day>1) ? onejan_next_monday_time : onejan.getTime(),
           this_date = new Date(this.getFullYear(), this.getMonth(),this.getDate(),0,0,0),
           this_time = this_date.getTime(),
   ...
   

5. getWeek()

   Date.prototype.getWeek = function() {
     var date = new Date(this.getTime());
     date.setHours(0, 0, 0, 0);
     date.setDate(date.getDate() + 3 - (date.getDay() + 6) % 7);
     var week1 = new Date(date.getFullYear(), 0, 4);
     return 1 + Math.round(((date.getTime() - week1.getTime()) / 86400000 - 3 + (week1.getDay() + 6) % 7) / 7);
   function getDay(yyyyMMdd) {
     return new Date(yyyyMMdd).getDay();
   ...
   

6. getWeek()

   'use strict';
   Date.prototype.getWeek = function() {
     var onejan = new Date(this.getFullYear(), 0, 1);
     return Math.ceil((((this - onejan) / 86400000) + onejan.getDay() + 1) / 7);
   };
   

7. getWeek()

   Date.prototype.getWeek = function() {
       var date = new Date(this.getTime());
       date.setHours(0, 0, 0, 0);
       date.setDate(date.getDate() + 3 - (date.getDay() + 6) % 7);
       var week1 = new Date(date.getFullYear(), 0, 4);
       return 1 + Math.round(((date.getTime() - week1.getTime()) / 86400000
           - 3 + (week1.getDay() + 6) % 7) / 7);
   Date.prototype.getWeekYear = function() {
   ...
   

8. getWeek()

   Date.prototype.getWeek = function () {
       var target  = new Date(this.valueOf());
       var dayNr   = (this.getDay() + 6) % 7;
       target.setDate(target.getDate() - dayNr + 3);
       var firstThursday = target.valueOf();
       target.setMonth(0, 1);
       if (target.getDay() != 4) {
           target.setMonth(0, 1 + ((4 - target.getDay()) + 7) % 7);
       return 1 + Math.ceil((firstThursday - target) / 604800000);
   

9. getWeek()

   Date.prototype.getWeek = function () {
       var determinedate = new Date();
       determinedate.setFullYear(this.getFullYear(), this.getMonth(), this.getDate());
       var D = determinedate.getDay();
       if (D == 0) D = 7;
       determinedate.setDate(determinedate.getDate() + (4 - D));
       var YN = determinedate.getFullYear();
       var ZBDoCY = Math.floor((determinedate.getTime() - new Date(YN, 0, 1, -6)) / 86400000);
       var WN = 1 + Math.floor(ZBDoCY / 7);
   ...