title: Format the date using Ruby on Rails
body: <p>The flickr api provides a posted date as unix timestamp one: "<code>The posted date is always passed around as a unix timestamp, which is an unsigned integer specifying the number of seconds since Jan 1st 1970 GMT.</code>"</p>
  
  <p>For example, here is the date '<code>1100897479</code>'. How do I format it using Ruby on Rails?</p>