use strict;
use warnings;
use Date::Calc qw/Add_Delta_Days/;

my ($mday,$mon,$year) = (localtime)[3..5];
my ($new_year,$new_month,$new_day) = Add_Delta_Days($year + 1900,$mon+1,$mday,-1);

my $file_name = sprintf("%04d%02d%02d.dat", $new_year,$new_month,$new_day);
print "Getting $file_name\n";