title: Date difference between two date variables with AM PM format.
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/1770564/getting-the-difference-between-two-time-dates-using-php">Getting the difference between two time/dates using php?</a>  </p>
  </blockquote>
  
  
  
  <p>I have two dates variable
  let $arrival_time="7.30 AM";
      $departure_time="8.30 PM";</p>
  
  <p>Then how can I calculate the time difference between these two variables in php ? </p>