title: Regular expression timezone
body: <p>I need a regular expression for valid time zone, tried the following one.<br />
  But I'm not sure about it.<br />
  Please help me to find out anything wrong in the following regular expression.</p>
  <h3>Edited:</h3>
  <p>Here colon and minutes are optional. how can i change it to mandatory.<br />
  If there is no minutes user should input 00 (+05:00).
  Please help me to solve this issue.</p>
  <pre><code>var chkzone = &quot;+05:30&quot;
  if(chkzone .match(/^(Z|[+-](?:2[0-3]|[01]?[0-9])(?::?(?:[0-5]?[0-9]))?)$/))
  {
      alert('works out');
  }
  else
  {
      alert(&quot;Time zone wrong&quot;)
  }
  </code></pre>