This used to be default behaviour for iCal (as with most other applications): you click the red button to close the open window but it will still run. A small dot remains under its symbol to show that this is the case. iCal could then pop-up notifications. For a while now, iCal closes when I hit the red button. There is no point under its icon in the dock.
How can I keep iCal running without having to minimise it -and live with an open window in the dock-, to get notifications of my events?
I checked and my preferences have Events set to notify me 10 minutes before. iCal is set to start at login. I'm running Sierra 10.12.6