Getting Error from the following script

CREATE PROC sp_calcualtteSI
AS
BEGIN
DECLARE @today DATETIME
SET @today = DATEADD(DAY, DATEDIFF(DAY, 0, CURRENT_TIMESTAMP), 0);
WITH cte_dates
AS ( SELECT DISTINCT
name ,
Pamount ,
Rateofint ,
cdate ,
CASE WHEN ISNULL(@today, @today) < DATEADD(MONTH,
1,
DATEADD(MONTH,
DATEDIFF(MONTH,
0, cdate), 0))
THEN ISNULL(@today, @today)
ELSE DATEADD(MONTH, 1,
DATEADD(MONTH,
DATEDIFF(MONTH,
0, cdate), 0))
END AS MonthEnd ,
ISNULL(@today, @today) AS End_date
FROM tbl_intestcalculate
),
cte_Alldates
AS ( SELECT name ,
Pamount ,
Rateofint ,
cdate ,
MonthEnd ,
@today AS today
FROM cte_dates
UNION
SELECT name ,
Pamount ,
Rateofint ,
DATEADD(MONTH, number, MonthEnd) ,
CASE WHEN DATEADD(MONTH, number + 1,
MonthEnd) < @today
THEN DATEADD(MONTH, number + 1,
MonthEnd)
ELSE @today
END ,
@today
FROM cte_dates c
CROSS JOIN ( SELECT number
FROM master..spt_values
WHERE type = 'p'
AND number BETWEEN 0 AND 11
) a
WHERE DATEADD(MONTH, number, MonthEnd) < @today
)
SELECT name ,
cdate ,
MonthEnd ,
Pamount ,
Rateofint ,
DATEDIFF(DAY, cdate, MonthEnd) AS No_Of_Days ,
ROUND( CAST(Pamount AS INT) * CAST(Rateofint AS INT) * DATEDIFF(DAY, cdate, MonthEnd)/ 36500, 2) AS SI
FROM cte_Alldates
END