If you would like to view all the events on your Website calendar in your Google Calendar, iCalendar or Outlook calendar, you can subscribe to a calendar 'feed'. Here are the instructions:
Open up your website calendar and your Google Calendar
On your website's Calendar click the "Subscribe to Calendar" button
Copy the calendar 'RSS' URL
Go to your Google Calendar and click the "Add other Calendar" + button, and click "From URL"
Paste in the calendar feed URL you copied previously, and click "Add Calendar"