Rules forBusiness Date option:

This option is only relevant to operations which correspond to individual server transactions. Such operations are the operations of facade classes and batch operations. Note that it is not applicable to workflow activity or deferred processing operations.
The field which is specified as the Business Date Field must be of type SVR_DATE or SVR_DATETIME.
The Business Date Field only takes effect when the operation is invoked by a remote client (either the HTTP client or a web services client) or by the Batch Launcher. It does not take effect for operations which are invoked directly from Java code. This is because the latter does not result in a new server transaction being started.
If the Business Date Field is set to null, curam.util.type.Date. kZeroDate or curam.util.type.DateTime. kZeroDateTime for a method invocation, it is ignored and the Business Date does not get overridden for that transaction. In this case the Business Date for the transaction will be either the current system date, or the overridden value specified in application properties - see the Date and DateTime JavaDoc documentation for more details.