夜以繼日 Save Sign in to save words Simplified: 夜以继日 On the HSK 7-9 vocabulary list, at CEFR level C2. yèyǐjìrì ㄧㄝˋ ㄧˇ ㄐㄧˋ ㄖˋ 男 女 night and day (idiom) continuous strenuous effort Character by character 夜(yè)night 以(yǐ)use 繼(jì)continue 日(rì)sun A Chinese word or character, or English Search Sources CC-CEDICT, CC BY-SA 4.0 pinyinjs, Apache-2.0 国际中文教育中文水平等级标准, 中华人民共和国教育部, MIT