Illinois looks to have adopted the IECC 2015, but I'm unable to locate Red Bud's requirements. In looking at IECC 2015, the following requirements would come in to play here:
C405.2.5 - Exterior Lighting Controls. Lighting for exterior applications other than emergency lighting that is intended to be automatically off during building operation, lighting specifically required to meet health and life safety requirements or decorative gas lighting systems shall:
1. Be provided with a control that automatically turns off the lighting as a function of available daylight.
2. Where lighting... (this section not applicable)
3. Where not covered in Item 2.... (this section not applicable)
All time switches shall be able to retain programming and the time setting during loss of power for a period of at least 10 hours.
I understand this to mean the exterior electric signage to be controlled via photocell/timeclock. Looking further into IECC though, you do not have to include this signage as part of the exterior lighting allowance per the following:
C405.5.1 - Exterior Building Power - The total exterior lighting power allowance.....
Exception: Lighting used for hte following exterior applications is exempt where equipped with a control device independent of the control of the nonexempt lighting:
1....
2. Advertising Signage or directional signage.
In my opinion the IECC is sending a conflicting message here as the exterior building power requirements only note that a separate control is required (and does not reference the section with it being part of a function of daylight). I could see this argued either way, but I would recommend it be placed on some sort of timeclock to automatically control the circuit.