diff --git a/Dam/Util.pm b/Dam/Util.pm
index 0c947a0..07c3316 100644
--- a/Dam/Util.pm
+++ b/Dam/Util.pm
@@ -29,7 +29,7 @@ our @EXPORT = qw(
 	array in_array index_in_array occurrences_in_array match_arrays array_uniq
 	fatal warning info
 	check_arguments
-	format_num format_pct format_date_dmy get_today_ymd
+	format_num format_pct format_date_dmy format_date_ymd get_today_ymd
 	csv_header csv_line
 );
 
@@ -375,7 +375,7 @@ sub in_array {
 	return FALSE if !defined($element) || !@array;
 	@array = @{$array[0]} if scalar @array == 1 && ref($array[0]) eq 'ARRAY';
 
-	my %hash_array = map { $_ => 1 } @array;
+	my %hash_array = map { (defined($_) ? $_ : '') => 1 } @array;
 	return defined($hash_array{$element}) ? TRUE : FALSE;
 }
 
@@ -639,9 +639,21 @@ sub format_date_dmy {
 
 
 
+sub format_date_ymd {
+	my @date = @_;
+
+	return '' if !@date;
+
+	@date = split('-', $date[0]) if scalar @date == 1;
+	return '' if is_empty($date[2]) || is_empty($date[1]) || is_empty($date[0]);
+	return sprintf("%04d-%02d-%02d", $date[0], $date[1], $date[2]);
+}
+
+
+
 =head2 get_today_ymd()
 
-Devuelve la fecha actual en el formato AAAA-MM-DD.
+Returns current date using the format YYYY-MM-DD.
 
 =cut