use Tie::PerFH;
tie $format, 'Tie::PerFH';

@date_info = qw( 12 3 1985 );
$format = '%02d-%02d-%04d';

open FH, ">some.file" or die "some.file error: $!";
select FH;
$format = '%02d/%02d/%04d';
printf $format, @date_info;
close FH;

select STDOUT;

printf $format, @date_info;