|
''Thirty days hath September'' is a traditional English mnemonic rhyme, of which many variants are commonly used in English-speaking countries to remember the lengths of the months in the Julian and Gregorian calendars. See also Knuckle Mnemonic. Here is one version of the rhyme attributed to Mother Goose: :''Thirty days hath September,'' :''April, June, and November.'' :''All the rest have 31,'' :''Except for February all alone,'' :''It has 28 each year,' :''but 29 each leap year.'' :''Thirty days hath September,'' :''April, June, and November :''All the rest have 31,'' :''Except for February.'' :''Thirty days hath September,'' :''April, June and November'' :''All the rest have thirty-one'' :''But February's but how much == History == The web site On This Day in Math 〔http://pballew.blogspot.com/2015/09/on-this-day-in-math-september-1.html〕 dates the rhyme at least to 1488. "The Plimpton Library has a copy of Anianus, Computus Manualis combined with Boethius, Arithmetica, which is probably the first book on mathematics printed in Strasburg. It has the first known printing of the little mnemonic that begins, “Thirty days hath September,” in Latin. Later versions differ from the medieval version in that September and November are often reversed, as in the Mother Goose variants above. As with any text that is still primarily transmitted orally, many versions exist. The first two lines are usually similar, with variations in the final lines relating to February. For instance, here is an unusual version that is longer and more rhythmic, with paired rhyming lines:〔This is a 19th-century variant of the rhyme from the American South.〕 :Thirty days have September, :April, June, and November. :All the rest have thirty-one, :no exceptions, but save one: :twenty-eight hath February, :but from this we still must vary :each four years when we do find :a small leap to twenty-nine. A shorter version that rhymes perfectly is from an unknown source and date: :''Thirty days have September,'' :''April, June, and November;'' :''Thirty-one the others date,'' :''Except in February, twenty-eight;'' :''But in leap year we assign'' :''February, twenty-nine.'' An old version that was traditionally sung (source unknown) is: :Thirty days hath September, :April, June, and November. :All the rest have thirty-one, :Except February alone, :Which has twenty-eight, in fine, :And each leap year twenty-nine. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Thirty days hath September」の詳細全文を読む スポンサード リンク
|