RFC 2445 describes a scheme for calendar interoperability.

This project implements core parts of RFC 2445 including a parser for recurrence rules, and date lists, and a mechanism for evaluating recurrence rules.

See the javadoc for known issues and caveats.

For questions and the occasional answer, join the user & developer group.

Features:

• evaluates recurrence rules that don't occur more frequently than daily
• evaluates groups of recurrence rules and handles exceptions
• Support for Joda-time dates and java.util.Date

To-Do:

• Direct support for recurrences more frequent than daily
• Support for user-defined timezones

Requirements:

• JDK 1.5

Maturity:

• Stable -- deployed in a large scale calendaring application
• Efficient for all common recurrences and reasonably efficient for others (Run tests for micro-benchmarks)
• No known non-halting behaviors