For a few months now, Google has been testing a new personalized search, which blends results from Gmail or Google Drive among the regular search results. The experiment is opt-in, only people who enable it get to see the personalized results.
Now, Google is adding more types of data, calendar appointments. Now, you can search for the things you're supposed to do on any particular day or to get more info on your appointments.
"With all that you juggle every day, its easy to lose track of appointments, plans, and reminders," Google explained
"You can learn your entire schedule for the day by searching for [what is on my calendar today]. Or if you'd want to know when you're meeting up with your friend Bryan for lunch, type [when am i meeting bryan]," it added.
If you've opted into the Gmail Field Trial, you'll start seeing these results soon if they haven't been enabled already. Otherwise, if you're curious, you can opt into the field trial here