title: Deleting External Cache Directory Periodically
body: <p>For my app I store map images in a cache on the external storage as to reduce calls to the API that I am using. Since this data is map data, it is subject to change over time. As a result these images should be updated every-so-often.</p>
  
  <p>How can I programmatically delete the cache directory periodically? Say for example, every week.</p>
  
  <p><em>Some extra thoughts:</em>
  Perhaps deleting the entire directory is not the best way to go about it. Perhaps I can check the "freshness" of each image, and delete the old ones?</p>