title: Informix: Date-Time conversion
body: <p>I am getting lost and nuts with the DATETIME in Informix.I have two problems which I can hardly solve:</p>
  
  <ol>
  <li>I have a DATETIME column (e.g. starttime) which I need to convert into an int value, e.g. seconds of year or epoch, or whatever. I found some conversion into utc, but this depends on the timezone the server runs, which I have no idea how to specify for the conversion.... Any other hint, how to convert it into seconds would be appreciated.</li>
  <li>I need to calculate the difference between two DATETIME-fields (e.g. endtime-starttime) and then sum it up. To my understanding the result is <em>interval day(13) to fraction(3)</em>. I need to convert the sum  once again into seconds, cause I need to update other values with this result.</li>
  </ol>
  
  <p>So, can anybody help me as to how to convert within a SQL-statement the different result-types?</p>