How to check that day is last day of month in php?

My previous question: how-to-find-current-day-no-in-month-in-php

Now I face another problem. Suppose I know that this monday is the 4th monday of the current month. Now how to check that this monday is also the last monday of the current month?

exa:1 
date: 27-01-2014

Using the code below, I get the name and number of a day:

day: monday   
day no :4th

This is the 4th monday of january and it is also the last monday of january. How to check that?

exa:2  
date: 20-01-2014   
day: monday   
day no :3rd

Here this monday is 3rd monday of january but not last monday of january.

So, in short, when I got a day number then how to check whether that the day number is last or not?

code:

$t=date('d-m-Y');
$dayName = strtolower(date("D",strtotime($t)));
$dayNum = strtolower(date("d",strtotime($t)));
$dayno = floor(($dayNum - 1) / 7) + 1

Answer

Just add 7 days (you still have a monday) to the date you have, and check if it’s in the same month.