title: Script or util to remove old backups
body: <p>I'm creating a backup strategy for a sharepoint server I'm setting up.</p>
  
  <p>Have got a backup running daily.</p>
  
  <p>In the long term I'd like to keep:</p>
  
  <pre><code>* Daily backups for the last week.
  * Weekly backups for the last month.
  * Monthly backups for the last year.
  * Yearly backups.
  </code></pre>
  
  <p>If I was writing in bash/cygwin I would find it fairly easy to write a script to purge backups that are not required by this strategy. However I would rather not have to install cygwin, I'd rather do it with native DOS scripting, or some other specialized tool. </p>
  
  <p>My DOS scripting skills are very primitive, so I was wondering if anyone else had a similar script/util I could use.</p>
  
  <p>Cheers!</p>