Wondering what's the logic behind bolded appointments in Cozi? Here's how it works:
In the past, any recurring appointment was in bold the FIRST time it happened. This is no longer the case. Recurring appointments are now always in regular text.
Any stand-alone (non-recurring) appointment will be in bold. This is to alert you that something new is on your calendar that is not normally there. For example a doctor's appointment you go to just once.
Finally, any recurring appointment that has been modified, will also be in bold. For example, let's say you normally have soccer for your kids on Tuesdays at 2:00pm. But on one week, it's been re-scheduled for 2:30pm. When you go in and modify that appointment, it will show up in bold for that one week, to alert everyone that there is something different about soccer that day.