In the design of Time & Chaos, we have given a great deal more thought to this subject that you might think and this has caused us to design the appointments and task list for very specific purposes.
Appointments take place on a specific day, perhaps even at a specific time. It is scheduled, it happens and its gone. You might want an alarm for a reminder so you don't miss it!
Tasks are to-do items that need to get done today, but are time-flexible. The goal, of course, is to mark everything done by the end of the day. If you know there are tasks you won't be able to do today, you can drag them to the calendar and reschedule them. As a fail-safe, if you forget to reschedule an item, but also forget to do it, Time & Chaos will remind you again tomorrow by continuing to show it on your Task List.
This help article applies to Time & Chaos 7