title: Number of days in a month
body: <p>I have a monthly amount that I need to spread equally over the number of days in the month.  The data looks like this:</p>
  
  <pre><code>Month       Value
  ----------- ---------------
  01-Jan-2012 100000
  01-Feb-2012 121002
  01-Mar-2012 123123
  01-Apr-2012 118239
  </code></pre>
  
  <p>I have to spread the Jan amount over 31 days, the Feb amount over 29 days and the March amount over 31 days.</p>
  
  <p>How can I use PL/SQL to find out how many days there are in the month given in the month column?</p>