Calculate Script Duration in PHP and BASH

#start of script
time_start=`date +%s`
#do stuff
sleep 65
#end of script
time_end=`date +%s`
time_elapsed=$((time_end - time_start))
echo "script executed in $time_elapsed seconds"
echo $(( time_elapsed / 60 ))m $(( time_elapsed % 60 ))s

Replace "sleep 65" above with the bash command you wish to time.

//put this at the start of your php script.
$s_mt = explode(" ",microtime());
//do stuff
//put this at the end of your php script
$e_mt = explode(" ",microtime());
$s = (($e_mt[1] + $e_mt[0]) - ($s_mt[1] + $s_mt[0]));
echo "script executed in ".$s." seconds";
echo ($s/60)."m ".($s%60)." s";

In both cases it would output:
script executed in 65 seconds
1m 5s