Google has expanded their Gmail field trial into Google Calendar to allow users who opt in to search Google for upcoming events and appointments on their calendar.
Google announced this on Google+ and shared that you can search for [what is on my calendar today] to show upcoming events right in your Google search results:
This also works with specific appointments, as Google explained "if you'd want to know when you're meeting up with your friend Bryan for lunch, type [when am i meeting bryan].
To opt into this trial, go to this page - note, it is not available for Google Apps users.
Forum discussion at Google+.
