use Time::Local;

my $beginning = 'Thu Oct 24 17:37:58 2007';
my $end       = 'Fri Oct 26 06:54:09 2007';
my %month = ( Jan => 0, Feb => 1, Mar => 2,
              Apr => 3, May => 4, Jun => 5,
              Jul => 6, Aug => 7, Sep => 8,
              Oct => 9, Nov => 10, Dec => 11 );

for ( $beginning, $end ) {
    my ( $mo, $dy, $hr, $mi, $se, $yr ) = ( split /[\s:]/ )[1..6];
    $mo = $month{$mo};
    $_ = timelocal( $se, $mi, $hr, $dy, $mo, $yr );
}

printf "%d sec elapsed\n", $end - $beginning;
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update: here's a more perlish way to initialize month numbers:

my $i=0;
my %month = map {$_=>$i++} qw/Jan Feb Mar Apr May Jun Jul Aug Sep Oct 
+Nov Dec/;
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I think you're probably looking for something like Date::Manip; although, depending on how large "large" is, you might look at Time::Local. It's more work but it's a lot faster.

This will do the trick:

(Note that I changed one of your time strings because a day name didn't agree with the other)

Update: You'll still need to wrap into a loop such as what graff did, but you can throw mine into a sub with two time strings as parameters, and have it return the elapsed time between them.

#!/perl/bin/perl -w

use strict;
use Time::Local;

my %months = (
  Jan => 1,
  Feb => 2,
  Mar => 3,
  Apr => 4,
  May => 5,
  Jun => 6,
  Jul => 7,
  Aug => 8,
  Sep => 9,
  Oct => 10,
  Nov => 11,
  Dec => 12
);  

my $beginning = 'Fri Oct 26 05:54:09 2007';
my $end       = 'Fri Oct 26 06:54:09 2007';

my @b = split(/[:\s]/, $beginning);
my @e = split(/[:\s]/, $end);

my $b = timelocal($b[5], $b[4], $b[3], $b[2], $months{$b[1]}-1, $b[-1]
+);
my $e = timelocal($e[5], $e[4], $e[3], $e[2], $months{$e[1]}-1, $e[-1]
+);

#my @new = localtime($b);
#printf "%04d%02d%02d\n", $new[5]+1900, $new[4]+1, $new[3];

my $elapsed = $e - $b;
print qq($elapsed seconds elapsed between the two events.\n);

__OUTPUT__
3600 seconds elapsed between the two events.
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use warnings;
use strict;

use Data::Dumper;
use Date::Manip;

my $beginning = 'Thu Oct 25 17:37:58 2007';
my $end       = 'Fri Oct 26 06:54:09 2007';

my $begin_date = ParseDate( $beginning );
print "From: $begin_date\n";

my $end_date   = ParseDate( $end );
print "To: $end_date\n";

my $error;
my $delta      = DateCalc( $begin_date, $end_date, \$error);

my $seconds = int( Delta_Format( $delta, 0, '%st' ) );
print "The number of seconds counted is $seconds seconds\n";
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