If there is a system clock, obtaining date/time doesn’t cause a data movement, i.e. date/time can be obtained ‘freely’. However, in some basic system architectures (like Raspberry PI or Arduno) there is no system clock. If in such architectures software (a ‘date/time functional process’) must be called that can supply them, identify an Exit for the request and an Entry for receipt of the date/time.
Another situation is where application A needs to verify the date/time a transaction has been processed in a remote application B. If application A has to delegate the request to B (in B a service (functional process) must be available to answer such requests), identify an Exit for the request and an Entry for receipt of the date/time.