Date Value Code For Conversion To Date in PHP or RUBY : <p>How do I convert a date value to a date in a csv file using PHP or Ruby?</p>

<p>Here is a sample of my column 'created_at' :
created_at
1309380645
1237178109
1303585711
1231175716
 That is the current date and I need mm/dd/yyyy format.
Thank you.</p>
