千載難逢 (Qiān zǎi nán féng) (1) extremely rare (idiom) (2) once in a blue moon (3) hard to encounter in a thousand years From https://dict.idioms.moe.edu.tw/bookView.jsp?ID=842 “Hard to encounter in a thousand years” means an opportunity that only occurs once in a long time. Such an opportunity that occurs only once in a thousand years is,…