Old Tango (one of the five seasonal festivals in the Edo period, which was taken place on the fifth of May): (May 5 [the old calendar]): 5＋5=10, 10÷6=1, the remainder is 4 => sakimake.
旧端午（5月5日(旧暦)）：5＋5＝10,10÷6＝1あまり4→先負