A digital calendar is a collaborative or personal time management software with a calendar that can be used to keep track of planned events. The calendar can also contain an appointment book, address book or contact list. Common features of digital calendars are that users can:
- Enter their own events
- Change the visibility (whether events, groups of events or entire calendars are private, shared with selected users/user groups, or are public)
- Subscribe to other calendars
- Set up meetings that can be shared or where others can be invited
- Different options for setting up reminders
There are several varieties of digital calendars. Some have the ability to be connected or synchronized with other calendars across different vendors. The iCalendar 1.0 and 2.0 specifications and its associated standards have been a cornerstone of the standardization and interoperability of calendar software across different vendors. A digital calendar can be viewed as an extension of many of the features provided by time management software such as desk accessory packages and computer office automation systems.