Inside OS X 10.8 Mountain Lion GM: Calendar & Reminders offer smart search, location-based alertsIn OS X Mountain Lion, Apple has replaced iCal with two separate Calendar and Reminders apps, harmonizing with iOS and improving the overall interface while making Reminders not just calendar event with alarms, but also location-based notifications.
The new Calendar app offers some streamlined interface tweaks, such as a sidebar Calendar listing that appears when you click on the Calendar button. Previously, this button created a popup menu. The new sidebar not only shows your configured calendars across all your accounts and calendar subscriptions, but also shows/hides a series of monthly calendars (below).
A second significant feature is smart search. Enter the beginnings of a search query, and Calendar now offers possible results, including Events with matching names, People identified with a particular event, or Locations. These search "tokens" work like searches in the Finder or Mail, so you can create specific searches that include multiple search criteria.
A third tweak is calendar picker popups, which let you select a date from a calendar, rather than just by adjusting the numbers of the month and day. This feature is widely used on the web when selecting dates.
Calendar also sports new Notification Center integration, so rather than popping up its own reminders, it forwards them though the new central repository for such events in Mountain Lion. This enables you to set your preference for notifications in one place (below).
While there isn't yet any direct support for showing Facebook events in Calendar, if you turn on the "Birthdays" calendar and sync Facebook with Contacts your calendar can be populated with the birthdays of everyone in your social circle. Additionally, you can opt to have alerts fire for birthdays (below), with however much advance warning you'd like (one week before, one or two days before, or early that day).
On page 2 of 2: iOS-style Reminders
On Topic: Mac OS X