Moment js get specific day of a month by week and day of week

Question

How to get second Tuesday of a given month or get third Thursday of a given month using moment js.

I tried finding a solution but was unsuccessful. I wrote it myself and posted the answer below and if you have a better solution u can answer your implementation.

Chiro

Probably I didn't get exactly what you are asking, but see here (and here) to get possible solution to similar question. – Kaela

they only work for one specific day. My requirement is for any day of any week. – Chiro

In the linked answer day of the week is "hard coded", but I think it's easy to get a more general solution starting from that answer. Anyway I've posted an updated answer with my attempt to get any day of any week. – Kaela

Answer 1

Here an updated version of the answer I linked in the comments. I've use weekday to use locale-aware day of the week, you can use day if you always want Sunday as 0 and Saturday as 6.

var getGivenDateOfMonth = function (startDate, dayOfWeek, weekNumber) {
  // Start of the month of the given startDate
  var myMonth = moment(startDate).startOf('month');
  // dayOfWeek of the first week of the month
  var firstDayOfWeek = myMonth.clone().weekday(dayOfWeek);
  // Check if first firstDayOfWeek is in the given month
  if( firstDayOfWeek.month() != myMonth.month() ){
      weekNumber++;
  }
  // Return result
  return firstDayOfWeek.add(weekNumber-1, 'weeks');
}

// Examples
var secondMondayOfJuly = getGivenDateOfMonth('2017-07-10', 1, 2);
console.log(secondMondayOfJuly.format());
var thirdFridayOfJuly = getGivenDateOfMonth('2017-07-10', 5, 3);
console.log(thirdFridayOfJuly.format());

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script>

Kaela

Answer 2

//get a preferred day of a month
var getGivenDateOfMonth = function (startDate, dayOfWeek, weekNumber) {
            var startOfMonth = moment(startDate).utc().startOf('month').startOf('isoweek');
            var dayOne = moment((moment(startDate, "YYYY-MM-DD").format("YYYY-MM") + "-01"),"YYYY-MM-DD");
            var studyDate;
            if (dayOne.isoWeekday() === 1) {
                studyDate = moment(startDate).utc().startOf('month').startOf('isoweek').add(dayOfWeek - 1, 'days')
                    .add(weekNumber, 'w');
            }
            else if (dayOne.isoWeekday() <= dayOfWeek) {
                studyDate = moment(startDate).utc().startOf('month').startOf('isoweek').add(dayOfWeek - 1, 'days')
                    .add(weekNumber - 1, 'w');
            } else {
                studyDate = moment(startDate).utc().startOf('month').startOf('isoweek').add(dayOfWeek - 1, 'days')
                    .add(weekNumber, 'w');
            }
            if (studyDate.month() == startOfMonth.month()) {
                studyDate = studyDate.subtract(1, 'w');
            }
            return studyDate;
        };

startDate is the date in a given month.
dayOfWeek is the moment js ISO day of week and
weeknumber is the week number(1,2,3,4) you want

Chiro

Answer 3

function nthDayOfMonth(month, year, day, weekNum){
   var nearestDay = moment(month + " " + year,"M YYYY").day(day);
   var nthDay = nearestDay.add(nearestDay.isSame(moment({month: month}),"month") ? weekNum - 1  : weekNum ,"weeks");
   return nthDay;
}

document.write(nthDayOfMonth(7,2017,3,3).format("L"));

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script>

Novelty

Answer 4

This code will get the date of the 2nd Tuesday of this month. Note: moment.js is obsolete now, use Luxon instead.

var DateTime = luxon.DateTime;

const second_tuesday = DateTime.local().startOf("month").plus({ weeks: 1, days: 3 });

console.log(second_tuesday.toLocaleString(DateTime.DATE_SHORT));

<script src="https://moment.github.io/luxon/global/luxon.min.js"></script>

Descendant

Sadly if your date is 01-04-2023 and you want 1st Week and week_day 0 (Sunday) you get back 02-04-2023 :( – Arhat