How to find business days in current month with Javascript?

Question

How can i create function for finding numbers of business days of current month? Can you code in simple javascript without Jquery.

    function daysInMonth(i         


        

Answer 1

OK, let's solve this one piece at a time.

The Date object in JavaScript has a method getDay. This will return 0 for Sunday, 1 for Monday, 2 for Tuesday, ... 6 for Saturday. Given that, we can conclude that we want to not count days whos getDay returns 0 or 6.

You already have a function to return the number of days in a month, so assuming that, we can loop over all of the days and check the result of getDay. daysInMonth makes the assumption that the month is zero based; so 0 = January.

I'd encourage you to try solving this on your own from here; otherwise read on.

---

Let's start with an isWeekday function. We need the year, month, and day:

function isWeekday(year, month, day) {
var day = new Date(year, month, day).getDay();
return day !=0 && day !=6;
}

We do exactly as we talked about above: we construct a Date, and use getDay to determine if it's a day.

Now we need to loop over all of the days in the month:

function getWeekdaysInMonth(month, year) {
var days = daysInMonth(month, year);
var weekdays = 0;
for(var i=0; i< days; i++) {
    if (isWeekday(year, month, i+1)) weekdays++;
}
return weekdays;
}

We loop over all of the days in the month. We add 1 when checking isWeekday because the day, unlike month, is 1 based. If it is, we increment weekdays, then return.

So we can use getWeekdaysInMonth like this:

var weekdays = getWeekdayInMonth(9, 2011); //9 = October.

Which will result in 21.

Answer 2

Arrow function style with chaining:

(
    (year, month) => 
        new Array(32 - new Date(year, month, 32).getDate())
        .fill(1)
        .filter(
            (id, index) =>
                [0, 6].indexOf(
                    new Date(year, month, index + 1).getDay()) === -1
                ).length
)(2017, 5)