Question: How do you control the scheduling of two separate AHUs if you want them to only be turned on during select hours of operation, but have them be controlled with temperature set points when it is engaged?

Background: I am trying to model a building made up of 2 thermal zones. The zones are conditioned by typical Carrier AHUs (R-22 for cooling and NG for heating). AHUs operate within a standard temperature setpoint range, and the thermometer is kept around 70 deg F. The occupants are able to turn the AHUs on and off by way of the thermostat and operate it as follows:

• The occupants turn on the AHU by way of the local thermostat in Zone 1 from 8am to 8pm, and let the temperature set points control the AHU from there.
• The occupants turn on Zone 2 by way of the local thermostat from 3pm-8pm on select days, and let the temperature set points do the the work thereon.
• When the building is not being used, from 8pm-8am, the AHUs are turned completely off.

How do I model such a schedule for my two AHUs?