I have pretty much the same idea as kevriley

declare @invaliddate varchar(6)

set @invaliddate = '081709'

declare @validdate datetime

select @validdate = convert(datetime, '20'+right(@invaliddate,2) + '-' + left(@invaliddate, 2) + '-' + substring(@invaliddate, 3,2))

print convert(varchar, @validdate, 112)

In this instance you can store the @validdate in a sql table as datetime datatype. But when you retrieve it you display it in the format required.

🙂