title: Regular expression to match 12-hour time
body: <p>I keep getting an error for this regular expression:</p>
  
  <pre><code>^((([1-9])|(1[0-2])):([0-5])(0|5)/s(A|P)M)$
  </code></pre>
  
  <p>It's supposed to be for a time that ends in 0 or 5.  So here are some that should work:</p>
  
  <ul>
  <li>1:25 PM  </li>
  <li>11:00 AM</li>
  <li>9:55 PM</li>
  </ul>
  
  <p>But I keep getting this error message:</p>
  
  <p>Internal error matching pattern <code>'^((([1-9])|(1[0-2])):([0-5])(0|5)/s(A|P)M)$'</code> against value <code>'1:00 PM'</code></p>
  
  <p>What am I doing wrong?</p>