Multiple sub-calendars with more than the maximum count of events (default is 20), will override reports from subsequent sub-calendars in the {calendar-events} macro. To reproduce, create a calendar with two sub-calendars, A and B. Add an event per day for the next 20 days for calendar A. Do the same on the same days for calendar B. Create a {calendar-events} macro, and only the 20 events from A will appear, one per day, even though it should report two events per day for ten days. Well, sometimes only the 20 events from A will appear, but other times I've found that 20 events will be shown that are a mixture of random events from the two calendars, but rarely will it show two events per day for ten days.