I have just noticed that Beyonce has an album with this title.
I use it as shorthand for “birthday.” I have no idea if that’s how Beyonce is using the term.
I wouldn’t be surprised if it was intended to mean “Beyonce Day”.
You think it’s a pun on bidet ?
Australian for “have a bad day”?
The album was intended to be released on her 25th birthday. Cite So I think both the birthday and the play on her first initial meanings apply.