Not actually addressing your problem but you could save a heap of typing when you initialise your holiday hashes. This

my %ny_holidays = ();
...
$ny_holidays{'20090101'} = 'New Years Day';
$ny_holidays{'20090115'} = 'MLK';
$ny_holidays{'20090219'} = 'Presidents day';
$ny_holidays{'20090406'} = 'Good Friday';
$ny_holidays{'20090528'} = 'Memorial Day';
$ny_holidays{'20090704'} = 'Independence Day';
$ny_holidays{'20090903'} = 'Labor day';
$ny_holidays{'20091122'} = 'Thanksgiving';
$ny_holidays{'20091225'} = 'Christmas Day';
[download]

could be written like this

my %ny_holidays = (
   '20090101' => 'New Years Day',
   '20090115' => 'MLK',
   '20090219' => 'Presidents day',
   '20090406' => 'Good Friday',
   '20090528' => 'Memorial Day',
   '20090704' => 'Independence Day',
   '20090903' => 'Labor day',
   '20091122' => 'Thanksgiving',
   '20091225' => 'Christmas Day',
   );
[download]

I hope this is of interest.