How to define thermostat schedules based on daytime and nighttime?
Daytime and nighttime would be defined by the value of the Site Direct Solar Radiation: if it's 0, then it's nightime, if its bigger than zero, then its daytime. Depending on this time difference, the limits for the thermostat schedules would be different as well.
Is this related to the greenhouse? Will it be heated or just ventilated? If it won't be heated. If you do want make thermostat like you describe, you can analyze the epw to come up with the thermostat times, and then create a thermostat schedule based on this.