I don't understand why you have to use Date::Manip or Date::Calc to calculate the difference between two timestamps :

use strict;
my $start = time();
do_stuff_that_takes_long_time();
my $end = time();
my $difference_in_seconds = $end - $start;
print "The process took $difference_in_seconds second(s)\n";
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perldoc -f time tells you what you need to know. And you should use the Perl documentation more often for your homework - it makes no business sense to disallow any module.

perl -MHTTP::Daemon -MHTTP::Response -MLWP::Simple -e ' ;    # The  
$d = new HTTP::Daemon and fork and getprint $d->url and exit;#spider
($c = $d->accept())->get_request(); $c->send_response( new   #in the
HTTP::Response(200,$_,$_,qq(Just another Perl hacker\n))); ' #  web
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