I had to use a CONVERT with the SUBSTRING Function as opposed to the CAST.
This works.
SELECT
CASE WHEN CAST(LEFT(Customer.STARTDATE, 2 AS VARCHAR(2)))
= '98' THEN CAST(substring(Customer.STARTDATE, 3, 2) AS VARCHAR(2))
WHEN LEFT(CAST(Customer.STARTDATE, 2) AS VARCHAR(2)) = '99' THEN
SUBSTRING(CONVFERT(VARCHAR(20),(Customer.STARTDATE, 3, 2) AS VARCHAR(2)) END AS LosstMo
FROM Customer
Thanks.
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