Sometimes, we want to get the week number of the month of a given date with JavaScript.
In this article, we’ll look at how to get the week number of the month of a given date with JavaScript.
How to get the week number of the month of a given date with JavaScript?
To get the week number of the month of a given date with JavaScript, we can calculate it by getting the first date of the month of the given date.
Then we add the day of the month of the given date plus the first day of the month minus 1, divide everything by 7 and take the ceiling of the whole expression.
For instance, we write:
const getWeekNumOfMonthOfDate = (d) => {
const firstDay = new Date(d.getFullYear(), d.getMonth(), 1).getDay();
return Math.ceil((d.getDate() + (firstDay - 1)) / 7);
}
const weekNumOfDate = getWeekNumOfMonthOfDate(new Date(2022, 1, 20))
console.log(weekNumOfDate)
to define the getWeekNumOfMonthOfDate function to do the calculation.
We get the first day of the month which is given by date d with:
const firstDay = new Date(d.getFullYear(), d.getMonth(), 1).getDay()
Then we add the date of the month with (d.getDate() + (firstDay - 1)).
And then we get the week number by dividing by 7.
Finally, we take the ceiling of the with Math.ceil to round that up to a whole number.
Therefore, the console log should log 3 since Feb 20, 2022 is in the 3rd week of February, 2022.
Conclusion
To get the week number of the month of a given date with JavaScript, we can calculate it by getting the first date of the month of the given date.
Then we add the day of the month of the given date plus the first day of the month minus 1, divide everything by 7 and take the ceiling of the whole expression.
