What a Diff'rence a Day Made, also recorded as What a Diff'rence a Day Makes, is a popular song originally written in Spanish by María Grever, a Mexican songwriter, in 1934 with the title Cuando vuelva a tu lado (When I Return to Your Side). The song is also known in English as What a Diff'rence a Day Makes, as popularized by Dinah Washington.\n\nWho sang what a difference a day makes first
Please answer and provide answer explanation.
María Grever
The relevant information to answer the above question is: "What a Diff'rence a Day Made", also recorded as "What a Diff'rence a Day Makes", is a popular song originally written in Spanish by María Grever, a Mexican songwriter, in 1934 with the title "Cuando vuelva a tu lado" ("When I Return to Your Side").

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Therefore, the answer is María Grever