Use Cut-Off Time.
If you need to offset the delivery date to the next business day in case the order is placed after the cut-off time, you can enable this feature and set the exact cut-off time:

All orders placed by cut-off time on a business day will be processed that same day. Orders placed after this time or outside business hours will be processed the next business day. Cut-off time should be the time zone of the company.
Available Delivery Dates.
The delivery dates available for the selection by the user could be managed through this setting. There are three available options:
- All dates. The user can select any day for delivery with no restrictions.
- Exclude weekends. The user can select any day, but the weekends and holidays specified in the SAP B1 company holiday calendar (Administration → System Initialization → Company Details → Holidays).
- Available Delivery Dates. The user can select only the dates allowed by the predefined query. The query should be created and saved in the Query Manager in SAP B1, it must return one column named DeliveryDate with the list of available dates in this column. To see the additional details please check the hint for the setting in the user interface.
Dates not available for the delivery will be greyed out in the calendar. If the user will try to select the unavailable date, he will receive the error message.