1. Install the extension me_google_calendar in extension manager and include the static template Google Calendar (me_google_calendar).
  2. Add the Plugin "Calendar" to a page
  3. Generate a google calendar record in a sysfolder of our choice (e.g. general storage) and fill in the fields
  4. Get the needed google calendar api key:
    Go to the Google Developer Console (https://console.developers.google.com/ ) and create a new project (it takes only some seconds).
    Once in the project, go to APIs & auth > APIs on the sidebar.
    Find “Calendar API” in the list and turn it ON (Google Calendar API)
    On the sidebar, click APIs & auth > Credentials.
    In the “Public API access” section, click “Create new Key”.
    Choose “Browser key”.
    If you know what domains will host your calendar, enter them into the box. Otherwise, leave it blank. You can always change it later.
    Your new API key will appear. It might take second or two before it starts working.
    Create a new calendar in google and under “access permissions” check “Make public”