Currently, the range_year is the date filled into the date_from.

This add-on allow the user to pick the date field used as the range_year
parameter into sequence generation.

Ex: date_from = '2018-10-01' and date_to = '2019-09-30'.
If you select 'date_to' as reference date, your range_year will be 2019
(instead of 2018 if you let the default 'date_from').

You can setup this field into sequences configuration.