Google calendar plugin, anyone? (It also runs as a standalone script once set up with OAuth credentials)
Here's my version as it stands...
So far, it includes the following features
- Clock
- Displays the next 9 events from your calendar, including ones that have started but not finished. Use the buttons to scroll through them
- Shows time until each event
- Backlight colour changes from green to red as an event draws closer (starting at 5 hours)
- Auto screensaver with configurable timeout
- Activity ticker using the graph LEDs even if the screen is off
- Auto-reloads the calendar when an event finishes (or can manual refresh with select button)
- If an event has a 'pop up' reminder, it will flash the graph LEDs during the reminder period, though you can't 'dismiss' the reminder.
- If an event has started but not finished, it shows time remaining until the event ends
Note: before I started this, I knew precisely zero python, so some of the code might not be good practice, but it seems to work.
Note 2: I've not yet tested it across Daylight Savings Times boundaries or anything like that, it's really not in the slightest bit Time Zone aware yet, which is probably a massive can of worms waiting to happen next spring! :D
[EDIT: Yes it was - hopefully it now behaves a bit better approaching and crossing timezone changes!]
It's reasonably well documented in the comments, but I guess I should get around to slapping it up on github at some point..

EDIT 2: Have thrown it up onto github now - the version I had here isn't the newest any more. : Code moved here