An ICS file is a calendar file saved in a universal calendar format used by several email and calendar programs, including Microsoft Outlook, Google Calendar, and Apple Calendar. It enables users to publish and share calendar information on the web and over email. ICS files are often used for sending meeting requests to other users, who can import the events into their own calendars.

Calendar files are saved in a plain text format. They contain information such as the title, summary, start time, and end time for the calendar event. The Calendar format also supports event updates and cancellations. You can quickly convert your ICS file to other popular file formats, such as .CSV, .PDF, .XLSX, and .HTML, with the ICS File Converter web program. NOTE: Apple Calendar was formerly known as Apple iCal but was changed in 2012 with the release of OS X Mountain Lion.