accounting for multiple codes per day in an oracle attendance query for counting absences

The following query counts how many absences an employee has over the specifies period of time.
My results are incorrect due to multiple codes existing on the same day.
There is a column that can be leveraged called ATT.CALENDARDAYID
How can I change the query below so if only counts one record if there are multiple codes of different values using the same ATT.CALENDARDAYID value?
For example, there may be a record for calendardayid 5000 with a code of ABS and another record with the same calendardayid 5000 with a code of NCNS.
The query below counts both instances, I only need one instance per calendardayid counted
Thanks!!

SELECT
CAST(USERS.EMPLOYEE_NUMBER AS varchar(10)) as EMPLOYEE_NUMBER,
to_char(ATT.BUILDINGID) as BUILDINGID,
to_char(ATT.YEARID) as YEARID,

sum(count(case when ATT_Code.Att_Code in ('ABS','HOSP','NOTE','NCNS') then 1 else 0 end)) over(partition by USERS.EMPLOYEE_NUMBER,ATT.BUILDINGID) as ABSTOTAL

FROM "SCHEMA"."ATT" "ATT"
INNER JOIN ATT_CODE on ATT.ATT_CODEID = ATT_code.id
INNER JOIN USERS on USERS.id = ATT.EMPLOYEEID
INNER JOIN SCHEMA.EMPLOYMENT EMPLOYMENT ON EMPLOYMENT.EMPLOYEEID = USERS.ID

WHERE
(ATT.yearid = '15')
AND (ATT.BUILDINGID NOT IN ('96','97','98','99'))
GROUP BY
USERS.EMPLOYEE_NUMBER,
ATT.BUILDINGID,
ATT.YEARID