Customer - Account End Date

Hi

I am using SQL Server 2008 R2 MDS and have a model called Customer which has the following two entities

( Customer & Account). The Account entity has a CUST ID attribute thus linking the Account to the Customer (one to one relationship).

However for an Account a customer can change (account code stays the same), how in MDS does one implement a Start Date//End Date  in the Account Entity if the Customer changes or is it better to just do an overwrite and therefore lose the history

Each Account has a unique Account Number

Regards

Tim

SQL DBA