Nice work, and it is great that you were also able to contribute changes to some formatter classes that other projects can now use as well. I hope you will stick around and continue working on apps for Haiku, there is certainly enough to keep busy! Even if you have only a few hours per week, I hope like me you will find contributing to the Haiku project fun, challenging and rewarding.
Thanks @Perelandra0x309 Ya there are a lot of apps in HaikuArchives to work on and the Calendar app itself requires a good amount of work for it to be a part of the release image and otherwise. So would be working on it. Contributing to the Haiku source interests me very much too so I’ll try to contribute there as well.