Or is the situation something like this

DECLARE @TABLE TABLE

(Number INT,

Date1 DATETIME,

Date2 DATETIME)

INSERT INTO @TABLE

SELECT 21,GETDATE(),GETDATE() UNION ALL

SELECT 21,GETDATE(),DATEADD(dd,2,GETDATE())

SELECT Number/CASE WHEN (datediff(dd,Date1,Date2)) = 0 THEN 1 ELSE (datediff(dd,Date1,Date2)) END

FROM @TABLE

Which case I used a case statement to check for 0 before dividing

you could right it differently but a case statement would work for you.

Thanks

Chris