Google provides a way to get a URL to poll the calendar data, meaning that you can use it as a user interface for data entry and manipulation, and extract the content for repurposing elsewhere.
"Add to Calendar" Links
Some event hosting silos such as Eventbrite offer "Add to Calendar" functionality to export events to a visitor's preferred calendar, including Google Calendar.
Constructing an Add to Google Calendar Link
It's possible to construct a link that adds an event to a Google Calendar. For example:
<a href="https://www.google.com/calendar/render?action=TEMPLATE& text=Your+Event+Name& dates=20140127T224000Z/20140320T221500Z& details=For+details,+link+here:+http://www.example.com& location=Waldorf+Astoria,+301+Park+Ave+,+New+York,+NY+10022& sf=true& output=xml">Add to Google Calendar</a>
More information can be found on this StackOverflow question.
Example post. Clicking the Google Calendar link produces:
- 2016-06-30: Outage  as noted in https://twitter.com/beep/status/748527397260111873
- 2014-10-15: Over the last couple days, I have run into the error "Failed to save event" on a few occasions when trying to add a new event. gRegor Morrill