$ perl -Mstrict -Mwarnings -E '
use constant {
    MONTH   => 0,
    DAY     => 1,
    TIME    => 2,
};
my $line = q{xxx yy yy:yy:yy xxx/xxxxx xxx xxxx xxx xxx};
my @fields = split / / => $line;
say $fields[TIME];
'
yy:yy:yy