title: Oracle: how to add minutes to a timestamp?
body: <p>I need to add 30 minutes to values in a Oracle date column.  I do this in my SELECT statement by specifying </p>
  
  <p><code>to_char(date_and_time + (.000694 * 31)</code></p>
  
  <p>which works fine most of the time.  But not when the time is on the AM/PM border.  For example, adding 30 minutes to <code>12:30</code> [which is  PM] returns <code>1:00</code> which is AM. The answer I expect is <code>13:00</code>.  What's the correct way to do this?</p>