The MIME type text/calendar is used to denote the presence of iCalendar format files. This MIME type is classified under the "text" category.

The iCalendar format uses the following extensions � ICAL, ICS, IFB and ICALENDAR. The iCalendar format was developed for the sole purpose of enabling users to share meetings, appoints and events through the Internet. These events, tasks etc. are made easier to share using this file type because it integrates well with applications and makes it easier to propose changes and display the relevant information like date, time etc automatically. It also makes it simpler to respond to invitations and having the successful appointments automatically marked on your personal calendar.

The iCalendar format is used and supported by a growing number of normal and web applications. The format was created by the Internet Engineering Task Force Calendaring and Scheduling Working Group. It was authored by a member of the Lotus Development Corporation. The iCalendar format is intentionally limited to describing only event data such as time, date, place, etc. It carries no information whatsoever to hint at the desired implementation of the data. Thus, it requires an external program to interpret the data.