Launch the LiveSlides app.
Open a presentation in PowerPoint.
Go to the Google Calendar website.
You'll need to make your calendar public by following these directions.
Copy the URL from your browser.
Paste the URL into the LiveSlides dialog and click "Insert".
A placeholder image will now appear in your slide.
Enter presentation mode to view the live web content.
Choose your presentation software and operating system for instructions on inserting Google Calendar into Keynote on Mac or PowerPoint on Windows.