Google Map Public Calendars
Google Maps Public Calendars
A New Feature in Google Calender is to be able to search Public Calenders and Events
"Now you can search the web for events and add them directly to your Google Calendar. Within Google Calendar, type an event search into the search box like "Symphony in San Francisco" and click "Search Public Events". You'll see a list of events that you can easily add to your Google Calendar."
more new features
There is also a Google Calendar API
The Maps for calendar only work when the user has inputted the location of the event.
All Events should have a location, therefore should be mapped.
Though please remember Google Calendar is still Beta.