use Time::Piece;

# ...

    $created = 'Time::Piece'->strptime($created, '%Y-%m-%d %R')->epoch;

# ...

            xp       => sprintf('%d', $data->{$monk}->{xp}),
            level    => $data->{$monk}->{level},
            age      => sprintf('%d', $data->{$monk}->{age}),
            by_age   => sprintf('%.4f', $data->{$monk}->{by_age}),
            posts    => sprintf('%d', $data->{$monk}->{posts}),
            by_posts => sprintf('%.4f', $data->{$monk}->{by_posts}),

# ...