Google has recently added a Smart Rescheduler in Google Calendar which is a Google Lab output. People spend lot of time in checking calendar, scheduling or rescheduling meetings, investigating other people's calendars, finding replacement conference rooms and rescheduling conflicts.
In order to help people, Google came up with a gadget called Smart Rescheduler to help you re-schedule an event by analyzing everybody's schedule, evaluating conflicts, obtaining conference rooms and proposing the best meeting times.
It uses some of Google's search experience to the problem of scheduling. Google experimented with using ranking algorithms to return the most relevant meeting times based on specified criteria like attendees, schedule complexity, conference rooms, and time zones. Just like Google search ranks the web, scheduling search algorithm returns a ranked set of the best candidate dates and times.
Once you turn it on, just select an event you'd like to reschedule, then click "Find a new time...":
You'll see ranked list of possible times for your meeting. By investigating the calendars others have shared with you, Google Calendar can make some educated guesses about how easy it might be to reschedule a conflicting meeting and even find you a replacement conference room nearby. This process is 100% automated — no Google employees are doing any work behind the scenes. You can refine the results by marking people as optional, changing the meeting duration, ignoring certain conflicts, or specifying the earliest and latest times you'll accept. The results will immediately update to reflect your new requirements.