This repository is a .NET library (Ical.Net) that implements the iCalendar specification (RFC 5545) for parsing, manipulating, and serializing calendar data in the ICS format. It provides core types such as Calendar, CalendarEvent, Todo, Journal, FreeBusy, VTimeZone, and Alarm, along with comprehensive support for recurrence rules (RRULE, RDATE, EXDATE), time zone handling via NodaTime, and free/busy computation. The architecture follows an object-oriented design with clear separation of concerns: data types (e.g., CalDateTime, Period, RecurrenceRule), calendar components, serializers (e.g., CalendarSerializer, PropertySerializer), and an evaluation engine for expanding recurring occurrences. The library is production-grade, with extensive test coverage (including a large corpus of ICS fixture files and regression tests for bug fixes), benchmarks for performance, and a logging abstraction. It is not a standalone application but a library designed to be consumed by .NET applications that need iCalendar functionality.