Using the Qualify statement on an Interval data type to filter out positive and null values

Question

I am trying to update a table to set the Dup_Flag column equal to 'Y' when the Dup1 value is negative.

I think I need to specify this condition on a Qualify clause but I don't know how to write it. Hoping to get some help here.

I am using Teradata SQL Assistant version 17.10.03.22

This is my code:

UPDATE Table1
FROM
(
    SELECT
    "Date",
    Call_GUID,
    DeDup_CID,
    Initial_Call_Time,
    Final_Call_Time,        
    (Initial_Call_Time) - MIN (Final_Call_Time) OVER (
    PARTITION BY DeDup_CID,
            "Date" 
    ORDER BY Initial_Call_Time ASC
        ROWS BETWEEN 1 PRECEDING 
        AND 1 PRECEDING) DAY(4) TO SECOND AS Dup1   
    FROM    Table1
QUALIFY Dup1 < 0 
)AS a
SET Dup_Flag = 'Y'
WHERE   Table1."Date" = a."Date"
    AND Table1.Call_GUID = a.Call_GUID
    AND Table1.Initial_Call_Time = a.Initial_Call_Time
    AND Table1.Final_Call_Time = a.Final_Call_Time

When I run this code, I get error message: Failed 5407. Invalid operation for DateTime or Interval.

This is how the data that results from the nested 'select' statement looks like:

Date	Call_GUID	DeDup_CID	Initial_Call_Time	Final_Call_Time	Dup1
09/21/2023	4B7FF52	2140000000	09/21/2023 08:01:17	09/21/2023 08:04:00	?
09/21/2023	A174742	2140000000	09/21/2023 08:03:33	09/21/2023 08:04:01	-0 00:00:26.180000
09/21/2023	C174756	2140000000	09/21/2023 08:18:28	09/21/2023 08:19:02	0 00:14:27.074000

This is what I am expecting to get from the 'qualify' statement:

Date	Call_GUID	DeDup_CID	Initial_Call_Time	Final_Call_Time	Dup1
09/21/2023	A174742	2140000000	09/21/2023 08:03:33	09/21/2023 08:04:01	-0 00:00:26.180000