title: DateTime.AddMonths adding only month not days
body: <p>Let's say, I have <strong>28th of February 2010</strong> and add one month to this date using <code>AddMonths(1)</code>...<br>
  the resulting date is <strong>March 28th</strong>, but not <strong>31st of March</strong>, which I want.<br>
  Is there a way to tweak that a bit so this works without adding custom code?</p>
  
  <p>Edit: I don't need the last day of a month, actually I need to add one month, but when its the last day of a month, I need to find the last day of the next month.</p>