I don't think your statement above is true.

You don't have to input any heating or cooling schedule for a given zone if you don't have a system supposed to condition the zone.

What is true is that if you want heating only or cooling only, you still need to input both a heating and a cooling schedule. For example if you want heating at 18°C and no cooling, put a heating thermostat schedule of 18°C 18C and a cooling thermostat schedule of 60°C, 60C, thus ensuring you'll never need any cooling.