I like the simple view we have today, but must admit i would like to be able to distinguish what zones will run at a glance, as suggested here. Look, i still know my zones by their zone numbers in my previous analog controller.
How about a series of small indicators (numbers, bullets, symbols etc) per day on the calendar, representing the zone number? I would prefer to always see the indicator, but dim if not active that day, darken or highlight when active. This addresses the color blind issue, as well. Admitedly this could be cluttered - so perhaps introduce a secondary (advanced or detailed) calendar view?