title: Enforce HH24:MM in input type=time?
body: <p>I want to use HTML5's <code>&lt;input type="time"&gt;</code>-field. It allows to support the user entering a time formatted string (like HH:MM). I want that users enter the time in format <code>HH24:MM</code> and with no (micro)seconds. </p>
  
  <p><a href="http://w3c.github.io/html-reference/input.time.html" rel="nofollow noreferrer">But the working draft</a> does not specify how to do that and what the current standard for the format is.</p>
  
  <p>How can I ensure users use only <code>HH24:MM</code>-times without using two select lists (one for hour and one for minute)?</p>