If you need to calculate how much time elapsed during this the queries execute on the page.
The answer is:
$start = microtime(true); $end = microtime(true); printf("Page was generated in %f seconds", $end - $start);
For reference, microtime() in a PHP predefined function.
Write $start just before your query or the beginning of the page and $end at the end of all the queries or at the end of page.