There's a relatively sophisticated Calendar app already, indeed: https://github.com/HaikuArchives/Calendar/ https://github.com/HaikuArchives/Calendar/ It had w

There's a relatively sophisticated Calendar app already, indeed: https://github.com/HaikuArchives/Calendar/ https://github.com/HaikuArchives/Calendar/ It had working Google Calendar sync at one point, dunno if it still is. It could definitely use some work, though.