title: UNIX find: opposite of -newer option exists?
body: <p>I know there is this option for unix's find command:</p>
  
  <pre><code>find -version
  GNU find version 4.1
  
      -newer file Compares the modification date of the found file with that of
          the file given. This matches if someone has modified the found
          file more recently than file.
  </code></pre>
  
  <p>Is there an option that will let me find files that are <em>older</em> than a certain file. I would like to delete all files from a directory for cleanup. So, an alternative where I would find all files older than N days would do the job too.</p>