Moment.js - How to get weekly data [startDate & endDate of each week] for given month excluding previous and next month date

Question

For August 2020 I need data like this : - As per https://www.epochconverter.com/weeks/2020

Week 31 - 2020-08-01 to 2020-08-02

Week 32 - 2020-08-03 to 2020-08-09

Week 33 - 2020-08-10 to 2020-08-16

Week 34 - 2020-08-17 to 2020-08-23

Week 35 - 2020-08-24 to 2020-08-30

Week 35 - 2020-08-31 to 2020-08-31

As per this info

This should work when we pass a year and month to a function as it should be generic

Required output

weekNumbers = ["Week 31", "Week 32", "Week 33", "Week 34", "Week 35", "Week 36"]; // week number should not start from 1. it should be continuos from last year.

weekList = []; // this should contain start and end date for each week

Thank you in advance

Answer 1

1. Common variables used :

   const monthIndex = 8; // give month index
   const year = 2020; // give year here
   

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2. Code to get week numbers of month : -

   const getWeekNumbers = (year, month) => {
     let firstWeek = moment(new Date(year, month, 1)).isoWeek();   
     let lastWeek = moment(new Date(year, month + 1, 0)).isoWeek();
   
     let out = [`Week ${firstWeek}`];
     if (firstWeek === 52 || firstWeek === 53) {
       firstWeek = 0;
     }
   
     for (let i = firstWeek + 1; i <= lastWeek; i++) {
       out.push(`Week ${i}`);
     }
     return out;
   };
   

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3. Code for getting week list data for month : -

   function getMomentDate(start, end) {
       return {
       startDate: moment([2020, monthIndex - 1, start]),
       endDate: moment([2020, monthIndex - 1, end])
     }
   }
   
   function weeks (month) {
       const weekStartEndDay = [];
       const first = month.day() == 0 ? 6 : month.day()-1;
       let day = 7-first;
       const last = month.daysInMonth();
       const count = (last-day)/7;
   
       weekStartEndDay.push(getMomentDate(1, day));
       for (let i=0; i < count; i++) {
           weekStartEndDay.push(getMomentDate((day+1), (Math.min(day+=7, last))));
       }
       return weekStartEndDay;
   }
   

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4. Calling and getting output : -

   const month = moment([year, monthIndex - 1])
   const weekNumbers = getWeekNumbers(year, monthIndex - 1);
   const weekList = weeks(month);
   console.log("weekNumbers", weekNumbers);
   console.log("weekList", weekList);
   weekList.forEach(date => {
       console.log("start - " + date.startDate.format('YYYY-MM-DD'), "\nend - " + date.endDate.format('YYYY-MM-DD'));
   });
   

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5. Console Output for August 2020

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6. REPL link : - https://repl.it/@SaHiLShiKalgar/WeekNumber-and-WeekList