If you have a spare tablet, you can turn it into an interactive calendar just by mounting it and keeping your calendar app of choice on the screen at all times. But if all you have is a spare monitor, check out Instructables member Alex Pine’s guide. He used a Raspberry Pi and an old monitor to show his Google Calendar on his wall.
Alex loaded Raspbian on his Raspberry Pi then installed the Iceweasel browser so he could go to Google Calendar’s online page. He also tweaked Iceweasel to start automatically and at full screen. Finally Alex turned off Raspbian’s mouse cursor and sleep timer. Schedule a visit to Alex’s Instructables page for the full walkthrough.