The iCalendar format, also known as "Internet Calandar" in Outlook, was designed to be viewed and shared with many different programs and services, including Google Calendar and Lotus Notes.

At first glance, your Microsoft Office Outlook calendar might seem incompatible with Apple's iCal; however, the .ics format, also known as iCalendar, is a common bond between these and many other ...

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”).