I don't know if this will apply but if you have a linux/unix system you could type "time perl name_of_your_script.pl" at the command prompt. This will give you the real, user, and sys time in milliseconds. If this is not on linux and you can't install modules then your first problem is that you are trying to substract Tue Jan 27 15:40:16 2004 from Tue Jan 27 19:45:56 2004. This will give you an error, hence the zero. So you need to parse out the time and subtract just the numbers.