How to compare two dates in php

Question

How to compare two dates in php if dates are in format \'03_01_12\' and \'31_12_11\' .

I am using this code:

$date1=date(\'         


        

Answer 1

format("%R%a")>0){
             echo "active";
       }else{
           echo "inactive";
       }
       echo "Remaining Days ".$diff->format("%R%a days");
?>