PL/SQL Stored Procedure in Oracle Application Express not running - oracle

Question

I created the stored procedure which compiled with no errors. But when I run exec sp_DATE_D(2005, 2006); I receive the following error:
ERROR at line 1:
ORA-01858: a non-numeric character was found where a numeric was expected
ORA-06512: at "SP_DATE_D", line 14
ORA-06512: at line 1
I expect my sample data to look like this as an example of one row:
DATE_KEY: 01/01/2005
FULL_DATE_DESCRIPTION: Monday, January 1, 2005
The procedure should populate from this point up until the last day of the 2nd parameter.
Stored Procedure:
CREATE OR REPLACE PROCEDURE sp_DATE_DD(v_START_YEAR IN INT, v_END_YEAR IN INT) AS
v_CURRENT_DATE DATE;
v_END_DATE DATE;
BEGIN
v_CURRENT_DATE := TO_DATE('0101' || v_START_YEAR, 'MMDDYYYY');
v_END_DATE := TO_DATE('1231' || v_END_YEAR, 'MMDDYYYY');
DELETE FROM DATE_D;
WHILE v_CURRENT_DATE <= v_END_DATE
LOOP
INSERT INTO DATE_D
(
DATE_KEY,
FULL_DATE_DESCRIPTION
)
VALUES
(
TO_DATE(v_CURRENT_DATE, 'MMDDYYYY'),
TO_CHAR(v_CURRENT_DATE, 'Day, Month DD, YYYY')
);
v_CURRENT_DATE := v_CURRENT_DATE + 1;
END LOOP;
END;
/
Table Definition:
CREATE TABLE DATE_D
(
DATE_KEY DATE NOT NULL,
FULL_DATE_DESCRIPTION VARCHAR2(64) NOT NULL,
CONSTRAINT DATE_DIMENSION_PK PRIMARY KEY (DATE_KEY)
);
To add:
Can't figure how out if its a format issue or I should convert.
Solution:
Modified Line 22 -
v_CURRENT_DATE,

Answer 1

The problem appears to be this line:
TO_DATE(v_CURRENT_DATE, 'MMDDYYYY'),
v_CURRENT_DATE is already a DATE variable. To pass it to the TO_DATE function Oracle has to convert it to a string, and the default string format for dates is DD-MON-RR. So if v_CURRENT_DATE already contains 1-JAN-2005, this is converted to the string '01-JAN-05', which is then passed to TO_DATE. But the format argument being passed to TO_DATE is 'MMDDYYYY', which doesn't match the string it's being handed ('01-JAN-05'), and so the TO_DATE function fails.
The solution is fairly simple: since v_CURRENT_DATE is already a DATE variable there's no need to call TO_DATE at all. Change the INSERT statement to:
INSERT INTO DATE_D
(
DATE_KEY,
FULL_DATE_DESCRIPTION
)
VALUES
(
v_CURRENT_DATE,
TO_CHAR(v_CURRENT_DATE, 'Day, Month DD, YYYY')
);