Hello Millzy,
I had the same problem with valid dates (2099-12-31). The Import Export Wizard in SQL Server automatically creates a table when the table does not exist when importing.
In Access (my source) the datetime field is created in SQL Server (my destination) as a SmallDatetime field.
SmallDatetime: Date and time data from January 1, 1900, through June 6, 2079
Datetime: Date and time data from January 1, 1753 through December 31, 9999
So I changed the definition in SQL Server from SmallDatetime to DateTime and the import succeeds.
Regards, Roel - Yellow & Red