ICalendar or ".ics" files are text files generated by scheduling and calendar applications. These files can then be uploaded to and synchronized with calendar applications on other electronic devices owned by the user. This file type is universal, so it can be used by any calendar software.
Files with the .ics extension are generated automatically when a schedule or event is saved on a calendar. With an uploaded .ics file, multiple members of the same team or company can keep track of each other's schedules and determine availability for a meeting or event. As of 2014, some programs that use the .ics file format include Microsoft Outlook, iCalendar and IBM Lotus Notes.