How can we have different formats for Timestamp in Import Maps?

We are trying to load data through Item Batches with the Data files generated from Import Map Template in PDH. In the attributes of Import Map there are two columns (Relationship Start Date and Relationship Start Date) with Data Type as Timestamp.

Is there a way to change the Data Type of these attributes?

If not, can we get any other timestamp formats other than the predefined timestamps?

Thanks ,

Sainatha