If you have ever wondered if you can join tables using one column that is a date data type and another that is a date time data type, then answer is -- Yes, sort of.  You can join a date to a date time, but the records will only come across if the time stamp is set to 12:00:00.  Any other time stamp and the record will be lost.  Therefore, it is probably best to convert the date time to a date OR insert a calculated column using a transformatioon that applies the date function to the date time column.