DateTime In C# + Compare Datetime
<ol>
<li>I need format type DateTime into: "dd/mm/yyyy". </li>
<li>I want to add, sub, compare between 2 DateTime.
         ex: 23/12/1991 > 2/1/1990.
              23/12/1991 - 20(days) = 3/12/1991
Could you help me, please.! Thank very much.! ^^</li>
</ol>
