the term “cake day” just makes me think of r*ddit. I’ve seen Lemon Day going around, but we probably want to avoid affiliation with lemon party.
not that we can tell anybody what to do anyway, and each instance could even have its own. anyway, it needs to be something that obviously means “anniversary” and doesn’t require explanation otherwise it’ll just be annoying
The Artist Formerly Known As Cake Day or TAFKACD if you’re into the whole brevity thing.
just come up with an unpronounceable symbol to replace it