Get the Nth Weekday of Any Month and Year with JavaScript

In today's challenge for a client of mine, I had to write a JavaScript function that returns the Nth Weekday of any given month and year. For example it can tell you what the 1st Monday is in December, 2017. It can do past, present and future so if you needed to know the 4th Friday in August of 1910, this function can tell you. If you need to know what the second Sunday of January 2050 is going to be, this JavaScript function will tell you!

Without any further time wasting, here is the JavaScript code that can determine the first, second, third, fourth or even fifth Monday, Tuesday, Wednesday, Thursday, Friday, Saturday or Sunday for any month and year you pass it:

JavaScript Code Returns Nth Weekday for any Given Month & Year:

<script>
/* JavaScript getMonthlyWeekday Function:
 * Written by Ian L. of Jafty.com
 *
 * Description:
 * Gets Nth weekday for given month/year. For example, it can give you the date of the first monday in January, 2017 or it could give you the third Friday of June, 1999. Can get up to the fifth weekday of any given month, but will return FALSE if there is no fifth day in the given month/year.
 *
 *
 * Parameters:
 *    n = 1-5 for first, second, third, fourth or fifth weekday of the month
 *    d = full spelled out weekday Monday-Friday
 *    m = Full spelled out month like June
 *    y = Four digit representation of the year like 2017
 *
 * Return Values:
 * returns 1-31 for the date of the queried month/year that the nth weekday falls on.
 * returns false if there isn't an nth weekday in the queried month/year
*/
function getMonthlyWeekday(n,d,m,y){
var targetDay, curDay=0, i=1, seekDay;
    if(d=="Sunday") seekDay = 0;
    if(d=="Monday") seekDay = 1;
    if(d=="Tuesday") seekDay = 2;
    if(d=="Wednesday") seekDay = 3;
    if(d=="Thursday") seekDay = 4;
    if(d=="Friday") seekDay = 5;
    if(d=="Saturday") seekDay = 6;
while(curDay < n && i < 31){
    targetDay = new Date(i++ + " "+m+" "+y);
    if(targetDay.getDay()==seekDay) curDay++;
}
if(curDay==n){
targetDay = targetDay.getDate();
return targetDay;
}else{return false;}
}//end getMonthlyWeekday JS function
</script>
<a href="JavaScript:var dy = getMonthlyWeekday(1,'Sunday','March', 2017);alert('1st Sunday in March, 2017 falls on March, '+dy);">Get first sunday in March, 2017</a><br />
<a href="JavaScript:var dy = getMonthlyWeekday(2,'Sunday','March', 2017);alert('2nd Sunday in March, 2017 falls on March, '+dy);">Get second sunday in March, 2017</a><br />
<a href="JavaScript:var dy = getMonthlyWeekday(5,'Sunday','March', 2017);alert('5th Sunday in March, 2017 falls on March, '+dy);">Get fifth sunday in March, 2017</a><br />
<a href="JavaScript:var dy = getMonthlyWeekday(4,'Friday','April', 2017);alert('4th Friday in April, 2017 falls on April, '+dy);">Get 4th Friday in April, 2017</a><br />
<a href="JavaScript:var dy = getMonthlyWeekday(5,'Monday','April', 2017);alert('5th Monday in April, 2017 falls on April, '+dy);">Get 5th Monday in April, 2017</a><br />
<a href="JavaScript:var dy = getMonthlyWeekday(3,'Wednesday','October', 1995);alert('3rd Wednesday in October, 1995 falls on October, '+dy);">Get 3rd Wednesday in October, 1995</a><br />
<a href="JavaScript:var dy = getMonthlyWeekday(4,'Wednesday','October', 1995);alert('4th Wednesday in October, 1995 falls on October, '+dy);">Get 4th Wednesday in October, 1995</a><br />
<a href="JavaScript:var dy = getMonthlyWeekday(4,'Wednesday','May', 1975);alert('4rd Wednesday in May, 1975 falls on May, '+dy);">Get 4th Wednesday in May, 1975</a><br />

Summary

That will do the job! All you have to do is copy and paste the above code in green into a blank text file and name it something like weekdays.html or test.html and open it in any web browser to test the code. Then feel free to alter it to fit your exact needs. Have fun!

 

 

 

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