struct tm {
               int tm_sec;         /* seconds */
               int tm_min;         /* minutes */
               int tm_hour;        /* hours */
               int tm_mday;        /* day of the month */
               int tm_mon;         /* month */
               int tm_year;        /* year */
               int tm_wday;        /* day of the week */
               int tm_yday;        /* day in the year */
               int tm_isdst;       /* daylight saving time */
           };

 tm_yday
              The number of days since January 1, in the range 0 to 365.

Tsunami julian_days # perl test2.pl 
Enter start date [yyyy/mm/dd]: 20080101
Enter end date [yyyy/mm/dd]: 20080220
A2008041231000.L2
A2008021231000.L2
A2008001231000.L2
Tsunami julian_days # perl test2.pl 
Enter start date [yyyy/mm/dd]: 2008/01/01  
Enter end date [yyyy/mm/dd]: 2008/02/20
A2008041231000.L2
A2008021231000.L2
A2008001231000.L2
Tsunami julian_days #

#!/usr/bin/perl -w

use POSIX;

$| = 1;

my $input;
my (@date_s, @date_e);

opendir(DIR, ".") || die "can't opendir: $!";
@dots = grep { ! /^\./ && /\.L2$/ } readdir(DIR);
closedir DIR;

print "Enter start date [yyyy/mm/dd]: ";
($input = <STDIN>) =~ /(\d{4})\/*-*(\d{2})\/*-*(\d{2})/;
$date_s[0] = mktime (0, 0, 0, $3, ($2-1), ($1-1900), 0, 0);
$date_s[2] = $1;
print "Enter end date [yyyy/mm/dd]: ";
($input = <STDIN>) =~ /(\d{4})\/*-*(\d{2})\/*-*(\d{2})/;
$date_e[0] = mktime (0, 0, 0, $3, ($2-1), ($1-1900), 0, 0);
$date_e[2] = $1;
(undef, undef, undef, undef, undef, undef, undef, $date_s[1] ,undef) = localtime($date_s[0]);
(undef, undef, undef, undef, undef, undef, undef, $date_e[1] ,undef) = localtime($date_e[0]);

foreach my $i (@dots)
{
        $i =~ /^A(\d{4})(\d{3})/;
        print $i . "\n" if (($1 >= $date_s[2] && $1 <= $date_e[2]) && (($2+0) >= $date_s[1] && ($2+0) <= $date_e[1]));  
}