Mass update of Benefit Balances (Wellness Points)

Good Morning All! 

I am using the following API to update the benefits balance for a person and I cannot seem to get past some conversion errors.  I have tried many things with no success.  Many thanks in advance.  G

declare

v_object_version_number number;

v_employee_number varchar(10);

v_effective_start_date date := '01-JAN-2020';

v_effective_end_date date :=  '31-DEC-4712';

v_person_id number;

v_per_bnfts_bal_id number;

v_bnfts_bal_id number;

v_benefit_balance varchar(5);

--v_effective_date date; -- := '01-JAN-2020';

v_temp_tabspace number;

data_line varchar2(100) := null;