How can I prevent Calendar from auto-closing notifications? A common scenario: I wake my Mac, notifications pop up and within 1 second, some of them close automatically. This happens for appointments that have a start time that's in the past (e.g. I open the Mac at 10:23 and the appointment was set for 09:00).  

I want those to stay open until I click 'Close'. I use these "appointments" as reminders to myself, having them disappear without acknowledgement makes them useless. These reminders generally don't need an exact time, but I need to see them at some point during the day I've set them for. 

How can I force the Mac to keep showing the notification until I interact with it? 

OSX 10.10.5, Calendar 8.0
In System Preferences → Nofications, set Calendar to Alerts.


  Banners appear in the upper-right corner and go away automatically. Alerts stay on screen until dismissed.