I use TimeTree mainly for its sharing features, which are excellent (it’s a Japanese app).

Are you looking for a service that includes email as well, or just a calendar?

Would the delivery take place quickly?

Me too I didn’t know there was a Reddit alternative, so I was using RSS feeds—then someone mentioned Lemmy in a comment, so here I am. Now I just need to wipe out Visa, and my boycott will be complete