php-icalendar-core is a modern, zero-dependency PHP 8.2+ library for parsing and writing iCalendar (.ics) data in full compliance with RFC 5545. It handles the genuinely hard parts of the calendar standard — recurrence rules (RRULE), timezones, and forward-compatible rich-text descriptions via STYLED-DESCRIPTION (RFC 9073) — behind a clean, strongly-typed API.
Highlights
- Full RFC 5545 compliance, including robust recurrence-rule (RRULE) support
- Zero runtime dependencies; native modern PHP — readonly properties, enums,
DateTimeImmutable, strong typing throughout - Clear strict and lenient parsing modes
- Memory-efficient streaming using generators
- Extensible for custom properties and components
php-icalendar-core will also serve as the iCalendar engine for the next-generation version of WebCalendar, which is currently under development and not yet released.
Learn more: my blog post introducing php-icalendar-core · documentation on DeepWiki · GitHub.