Is there a way to validate or limit dates and times in a DateTime user option within offering request form?

We have a requirement for a DateTime user option in a service offering. This field will be used to ask the requestor to pick a date and time for a meeting, but that time must be within Monday to Friday, 9am-3pm Eastern time. We would like to either limit the choices of the DateTime picker to within that time window, or use a validation business rule to display an error if they choose outside of that time window.

Has anyone managed to achieve this within SMAX?