Fred,
I don't need the current date.
The contract BO entry (contract.ValidityPeriod.TimePointPeriod.StartTimePoint.DateTime) is storing the begin datetime of the contract.
I just need to convert that to the date datatype of my custom BO.
(The other alternative is to declare my custom BO element as a datetime - but it's not so simple as that. A custom BO can only use GLOBAL_DateTime datatype. And, the assignment also didn't work - similar compile / activation error message).