title: Delete files older than 3 months old in a directory using .NET
body: <p>I would like to know (using C#) how I can delete files in a certain directory older than 3 months, but I guess the date period could be flexible. </p>
  
  <p>Just to be clear: I am looking for files that are older than 90 days, in other words files created less than 90 days ago should be kept, all others deleted.</p>