When you have the DateID as an int that represents a real date it can be good to be able to use SSIS to convert datetime to int in an easy way.
In this blog post by Mike Davis shows a very easy to do it. You can find his code below
(year(@[User::dtStartDate]) * 10000)+(month( @[User::dtStartDate]) * 100)+Day( @[User::dtStartDate])