iCalendar

iCalendar (also known as iCal) is a standard file format (RFC 5545) for exchanging calendar and scheduling information, such as events, appointments, and tasks, between applications and systems. It uses a plain text format with specific syntax to represent calendar data, enabling interoperability across different calendar software like Google Calendar, Apple Calendar, and Microsoft Outlook. The format supports properties like start/end times, recurrence rules, attendees, and descriptions.

Also known as: iCal, RFC 5545, icalendar, ics format, calendar file format

Why learn iCalendar?

Developers should learn iCalendar when building applications that involve calendar integration, event management, or scheduling features, such as booking systems, meeting planners, or productivity tools. It is essential for parsing, generating, or syncing calendar data across platforms, ensuring compatibility with widely used calendar services without relying on proprietary APIs. Use cases include exporting events from a web app, importing schedules into user calendars, or handling recurring events in a standardized way.

Learning Resources

• docs: RFC 5545 Specification
• docs: iCalendar Wikipedia Page
• tutorial: iCalendar Tutorial by iCalendaring.org
• docs: Working with iCalendar in Python (icalendar library)
• docs: MDN Web Docs: iCalendar Format