customer order cut off times and dates

Ivan__Torr 

Ah you didn't mention that point originally.
Depending on what determines a business day, you might be able to do this by adding AND or OR sections to the IIf criteria.
For example if business days are Mon-Fri only, then you could use the Weekday function for this. See MS Access: Weekday Function (techonthenet.com). 

For example Sunday = 1 through to Saturday = 6 (though this may be different for you).

Anyway, assuming the above is true, only orders made on Mon-Thur before say 19:00 get next day delivery. If so then try something like this:

IIf((Weekday(Date())>=2 And Weekday(Date())<=5 And OrderTime<#19:00#, Date()+1, Date()+2)

However, that doesn't take into account public holidays which may also prevent next day delivery.

Anything more complex than the above would best be done by creating a user defined function.

Hope that helps