set_time_limit () - CPU time or elapsed time?

This function limits the"execution time" for a script. Is this CPU time or elapsed (wall-clock) time? I'm asking because I'm running Win7 in a VirtualBox VM under OS X Mavericks. I've got an app that runs a number of scripts, using PHP 5.5.9. All runs correctly, but quite slowly, and a one script reports taking 20 secs or so of elapsed time when I might have expected 2 or 3 at most (as the same script running under OS X does). I know that there is a note in the online doc for this function that says that under windows, extra time such as database calls is included. Would that include SQLite calls which wouldn't be included for the OS X version? I've got a windows user whose scripts are actually running out of time, so I may have to add a php_value to the apache config to crank up the time limit. Tim Streater Bedford House Kake St Waltham CT4 5RZ 01227 700322