1. Open up a terminal window.
2. Add the necessary repository with the command sudo add-apt-repository ppa:atareao/atareao
3. Update apt with the command sudo apt-get update
4. Install the applet with the command sudo apt-get install calendar-indicator
5. Open Whisker Menu and search for calendar-indicator.
6. Enable google login and login with your information.
7. Now you have a calendar option near the clock in the notification section of the panel that displays your calendar events.