One possible way is to have a page that lists the full details of the events on that day; navigated to by clicking on the day in the respective calendars.
A Tooltip that show the notes on hovering the displayed event is also an option, but doesn't work well on mobile.
Another option would be to list the notes above the calendar when you click on the shown event, this seems good because it is more fluid than having to back out of each individual summary page, but it may cause jumpyness in the location of the calendar.
One possible way is to have a page that lists the full details of the events on that day; navigated to by clicking on the day in the respective calendars.
A Tooltip that show the notes on hovering the displayed event is also an option, but doesn't work well on mobile.
Another option would be to list the notes above the calendar when you click on the shown event, this seems good because it is more fluid than having to back out of each individual summary page, but it may cause jumpyness in the location of the calendar.