my $end_year = substr( $end_date[0], 0, 4 );
my @month_headings = ();
while ( $begin_month <= $end_month || $begin_year < $end_year ) {
while ( $begin_year <= $end_year && ( $begin_year != $end_year || $begin_month <= $end_month ) ) {
push(
@month_headings,
$column_headings_formatting
-