title: Round formatted time value to the nearest half-hour
body: <p>I need 0:30 through 0:59 to round down to 0:30.<br />
  I need 0:00 through 0:29 to round up to 0:30.</p>
  
  <p>Example: 08:56 will round down to 08:30 where 09:00 and 09:01 will need to round up to 09:30.<br />
  Seconds should be omitted or rounded to :00</p>