If you’re a Google Calendar user, you may have had issues adding events to your calendar when someone sends them to you attached to an email in iCal format (the files usually looks like “invite.ics”).

When users install third-party calendar software, such as Entourage, the installation process may displace iCal as the the default for accepting invitations and other calendar-related functions. This ...

Apple designs its computers so you can transfer data and share information between systems easily. This works for nearly all the OS X-native applications, including iCal, the calendar application.