SubFields

Subfield names:

years, months, weeks, days, hours, minutes, seconds, nanoseconds

For example:

has_field 'duration'         => ( type => 'Duration' );
has_field 'duration.hours'   => ( type => 'Hour' );
has_field 'duration.minutes' => ( type => 'Minute' );

Customize error message 'duration_invalid' (default 'Invalid value for [_1]: [_2]')