# ical.net

> open source iCal library for .NET

**Wikidata**: [Q128799387](https://www.wikidata.org/wiki/Q128799387)  
**Source**: https://4ort.xyz/entity/ical-net

## Summary
ical.net is an open source iCal library for .NET, providing tools to handle iCalendar data in .NET applications. It evolved from DDay.iCal, rebranded in 2016 under the MIT License with performance enhancements. As free software, it allows users to run, study, change, and distribute it freely.

## Key Facts
- Open source iCal library for .NET, classified as software library and free software.
- Main subject is iCalendar.
- Titles: "ical.net" starting from 2016; previously "DDay.iCal" until 2016.
- Alias: DDay.iCal.
- License: MIT License.
- Stable versions include 4.3.0 (2024-10-13), 4.1.7 (2024-10-22), 4.1.8 (2024-10-22), 4.1.9 (2024-10-22), 4.1.10 (2024-10-22), 4.1.11 (2024-10-22), 4.2.0 (2024-10-22), 4.3.1 (2024-10-14), 5.0.0 (2025-06-17), 5.1.0 (2025-07-16), 5.1.1 (2025-10-06), 5.1.2 (2025-11-13), 5.1.3 (2025-12-01), and preferred 5.1.4 (2025-12-13).
- Rebranding announced on 2016-07-04 by Rian at https://rianjs.net/2016/07/dday-ical-is-now-ical-net, titled "dday.ical is now ical.net and available under the MIT license with many performance enhancements | rianjs.net".
- Source code repository: https://github.com/rianjs/ical.net, associated with GitHub and mirrors.
- Described at URL: https://rianjs.net/2016/07/dday-ical-is-now-ical-net (English).
- Stack Exchange tags: https://stackoverflow.com/tags/ical-dotnet, https://stackoverflow.com/tags/dday.
- Copyright status: copyrighted.
- Related to free software class with 120 sitelinks.

## FAQs
**What is the history of ical.net's naming?**  
It started as DDay.iCal, which ended in 2016, then became ical.net from 2016 onward. The change was detailed in a 2016-07-04 blog post by Rian.

**What license does ical.net use?**  
ical.net is distributed under the MIT License, enabling free running, study, changes, and distribution as free software.

**What are the latest stable versions of ical.net?**  
The preferred stable version is 5.1.4 released on 2025-12-13. Other recent stables include 5.1.3 (2025-12-01), 5.1.2 (2025-11-13), and 5.1.1 (2025-10-06).

**Where can I find ical.net's source code and releases?**  
Source code is at https://github.com/rianjs/ical.net. Releases like v4.3.0 (2024-10-13) and v5.1.4 (2025-12-13) are on GitHub.

**What community discussions exist for ical.net?**  
It appears in Stack Exchange tags at https://stackoverflow.com/tags/ical-dotnet and https://stackoverflow.com/tags/dday.

**Is ical.net focused on a specific standard?**  
Yes, its main subject is iCalendar, making it a specialized .NET library for that format.

## Why It Matters
ical.net fills a critical gap for .NET developers needing robust iCalendar parsing, creation, and manipulation without proprietary dependencies. By open-sourcing under MIT and evolving from DDay.iCal with performance boosts since 2016, it empowers free software principles—users can inspect, modify, and redistribute it fully. Its steady release cadence through 2025, tracked on GitHub, ensures reliability for calendar apps, event systems, and integrations, while Stack Exchange tags reflect real-world adoption. As copyrighted free software tied to iCalendar, it advances open ecosystem tools, reducing barriers for .NET projects handling RFC 5545-compliant data.

## Notable For
- Rebranding from DDay.iCal to ical.net in 2016 with MIT License and performance enhancements.
- Extensive stable release history, from 4.1.7 series in 2024 to preferred 5.1.4 in 2025-12-13.
- Free software status allowing full user freedoms, linked to 120 sitelinks.
- Dedicated Stack Exchange tags: ical-dotnet and dday.
- GitHub-hosted evolution under rianjs, with precise release tracking.

## Body
### History and Naming
ical.net originated as DDay.iCal, which operated until 2016. In 2016, it rebranded to ical.net, as announced on 2016-07-04 by Rian in the English-language post "dday.ical is now ical.net and available under the MIT license with many performance enhancements" at https://rianjs.net/2016/07/dday-ical-is-now-ical-net. This site also describes it further in English. The title "ical.net" applies from 2016 onward, while "DDay.iCal" marks the prior phase.

### Classification and Status
It instances as both a software library and free software. Free software here means distribution terms permit users to run, study, change, and distribute it plus modified versions, connected to a class with 120 sitelinks. Copyright status remains copyrighted. Its Wikidata description confirms: open source iCal library for .NET. Main subject is iCalendar.

### Licensing
Under MIT License since the 2016 rebrand, supporting its free software nature.

### Versions and Releases
All listed are stable versions ( qualifier).  
- 4.3.0: 2024-10-13, https://github.com/ical-org/ical.net/releases/tag/v4.3.0 (accessed 2024-10-14).  
- 4.1.7: 2024-10-22, https://github.com/ical-org/ical.net/releases/tag/v4.1.7 (accessed 2024-11-15).  
- 4.1.8: 2024-10-22, https://github.com/ical-org/ical.net/releases/tag/v4.1.8 (accessed 2024-11-15).  
- 4.1.9: 2024-10-22, https://github.com/ical-org/ical.net/releases/tag/v4.1.9 (accessed 2024-11-15).  
- 4.1.10: 2024-10-22, https://github.com/ical-org/ical.net/releases/tag/v4.1.10 (accessed 2024-11-15).  
- 4.1.11: 2024-10-22, https://github.com/ical-org/ical.net/releases/tag/v4.1.11 (accessed 2024-11-15).  
- 4.2.0: 2024-10-22, https://github.com/ical-org/ical.net/releases/tag/v4.2.0 (accessed 2024-11-15).  
- 4.3.1: 2024-10-14, https://github.com/ical-org/ical.net/releases/tag/v4.3.1 (accessed 2024-11-15).  
- 5.0.0: 2025-06-17, https://github.com/ical-org/ical.net/releases/tag/v5.0.0 (accessed 2025-06-17).  
- 5.1.0: 2025-07-16, https://github.com/ical-org/ical.net/releases/tag/v5.1.0 (accessed 2025-07-17).  
- 5.1.1: 2025-10-06, https://github.com/ical-org/ical.net/releases/tag/v5.1.1 (accessed 2025-10-20).  
- 5.1.2: 2025-11-13, https://github.com/ical-org/ical.net/releases/tag/v5.1.2 (accessed 2025-11-13).  
- 5.1.3: 2025-12-01, https://github.com/ical-org/ical.net/releases/tag/v5.1.3 (accessed 2025-12-02).  
- 5.1.4: Preferred, 2025-12-13, https://github.com/ical-org/ical.net/releases/tag/v5.1.4 (accessed 2025-12-14).

### Source Code and Repositories
Primary source code repository at https://github.com/rianjs/ical.net. Qualifiers link to GitHub and mirrors.

### Community and Tags
Associated Stack Exchange tags: https://stackoverflow.com/tags/ical-dotnet and https://stackoverflow.com/tags/dday. These reflect developer discussions on ical.net and its predecessor.

## References

1. [Release 4.3.0. 2024](https://github.com/ical-org/ical.net/releases/tag/v4.3.0)
2. [Release 4.1.7. 2024](https://github.com/ical-org/ical.net/releases/tag/v4.1.7)
3. [Release 4.1.8. 2024](https://github.com/ical-org/ical.net/releases/tag/v4.1.8)
4. [Release 4.1.9. 2024](https://github.com/ical-org/ical.net/releases/tag/v4.1.9)
5. [Release 4.1.10. 2024](https://github.com/ical-org/ical.net/releases/tag/v4.1.10)
6. [Release 4.1.11. 2024](https://github.com/ical-org/ical.net/releases/tag/v4.1.11)
7. [Release 4.2.0. 2024](https://github.com/ical-org/ical.net/releases/tag/v4.2.0)
8. [Release 4.3.1. 2024](https://github.com/ical-org/ical.net/releases/tag/v4.3.1)
9. [Release 5.0.0. 2025](https://github.com/ical-org/ical.net/releases/tag/v5.0.0)
10. [Release 5.1.0. 2025](https://github.com/ical-org/ical.net/releases/tag/v5.1.0)
11. [Release 5.1.1. 2025](https://github.com/ical-org/ical.net/releases/tag/v5.1.1)
12. [Release 5.1.2. 2025](https://github.com/ical-org/ical.net/releases/tag/v5.1.2)
13. [Release 5.1.3. 2025](https://github.com/ical-org/ical.net/releases/tag/v5.1.3)
14. [Release 5.1.4. 2025](https://github.com/ical-org/ical.net/releases/tag/v5.1.4)
15. [Release 5.2.0. 2025](https://github.com/ical-org/ical.net/releases/tag/v5.2.0)
16. [Release 5.2.1. 2026](https://github.com/ical-org/ical.net/releases/tag/v5.2.1)
17. [dday.ical is now ical.net and available under the MIT license with many performance enhancements | rianjs.net. 2016](https://rianjs.net/2016/07/dday-ical-is-now-ical-net)