use strict;
use warnings;

my %daysOffsetTV = (
   0 => 86400 * 2,
   1 => 86400 * 3,
   2 => 86400 * 4,
   3 => 86400 * 5,
   4 => 86400 * 6,
   5 => 86400 * 7,
   6 => 86400,
   );

my $nowTV = time();
my $dayOfWk = ( localtime( $nowTV ) )[ 6 ];

my $prevWkFriTV = $nowTV - $daysOffsetTV{ $dayOfWk };
my( $friDay, $friMth, $friYr ) =
   ( localtime( $prevWkFriTV ) )[ 3 .. 5 ];
$friMth += 1;
$friYr  += 1900;
my $endDate =
   sprintf q{%04d%02d%02d%02d}, $friYr, $friMth, $friDay, 23;

my $prevWkMonTV = $prevWkFriTV - 86400 * 4;
my( $monDay, $monMth, $monYr ) =
   ( localtime( $prevWkMonTV ) )[ 3 .. 5 ];
$monMth += 1;
$monYr  += 1900;
my $startDate =
   sprintf q{%04d%02d%02d%02d}, $monYr, $monMth, $monDay, 0;

print
   qq{Starting date: $startDate\n},
   qq{  Ending date: $endDate\n\n};

while( <DATA> )
{
    my $timestamp = ( split m{,} )[ 0 ];
    print
       unless $timestamp lt $startDate or $timestamp gt $endDate;
}

__END__
2009030822,3558,1.68
2009030823,6385,5.47
2009030900,7485,1.82
2009030901,8563,4.35
2009031322,8860,3.68
2009031323,39224,14.16
2009031400,34553,7.34
2009031401,7353,5.74

##</code><code>##

Starting date: 2009030900
  Ending date: 2009031323

2009030900,7485,1.82
2009030901,8563,4.35
2009031322,8860,3.68
2009031323,39224,14.16