Hi QA,
I am not sure what you mean by a "night run" so I'll take a stab (in the
dark) as to what I think you mean.
I assume you need to schedule work over night (after 5:00 PM for example).
Project schedules tasks based upon the working time as defined in the Project
Calendar. Choose Tools > Change Working Time and edit the project calendar
to include the night hours. You may want to take a look at the "Night-Shift"
calendar in Project to get a sense of how to set up working time that spans
over midnight.
I hope this helps. Let us know how you get along.
Julie