calendarial.net
Calendar interoperability is a genuine technical problem, and the .net reads as network and infrastructure rather than as a consumer product. A calendaring API, a sync service, a federation protocol or a developer tool all sit naturally here.
Calendarial itself is a coined adjective from a word everyone knows, which is the right way to build a software brand: the root explains, the invented ending makes it ownable.
The consumer reading works too, for a scheduling app, a booking product or an events platform. Scheduling is crowded and every descriptive name went years ago, so a coined word still saying “calendar” in its first five letters is a real find.
Eleven letters, entirely phonetic, no hyphen, no silent characters, surviving being spelled out over a phone call.
The name is listed for sale. Offers welcome.