use POSIX qw(strftime);

$time= localtime(time-(24*60*60));
$yesterday = strftime( '%d/%m/%y', $time);

##</code><code>##

`grep "$yesterday" logfile.log | wc -l`

##</code><code>##

open(LOGFILE,"<", "access.log")or die"Could not open log file.";
my @logfile = <LOGFILE>
my $hits = grep /$yesterday/, @logfile;