title: convert epoch time to human readable without a dedicated function
body: <p>I'm writing a macro for slick-edit (with the C similar language slick-C)<br>
  As far as I found there are no time functions to help me convert epoch time (1321357827) to a human readable date and time  </p>
  
  <p>(if any of you knows how to do it in slick-C it's great, those of you who doesn't know it - assume C without time.h or any other libs)</p>