Talmud (Rodkinson Edition) — Book 2…
“ At three periods of the year money is drawn from the treasury (of the Shekalim) ; viz.: Half a month before Passover, half a month before Pentecost, and half a month before the Feast of Booths. The same dates are also the terms for the obligation of cattle-tithing, so says R. Aqiba. Ben Azai says: "The dates for the latter terms are the twenty-ninth of Adar, the first of Sivan, and the twenty-ninth of Abh." R. Eliezer and R. Simeon both say: "The first of Nissan, the first of Sivan, and the twenty-ninth of Elul." But why do they say the twenty-ninth of Elul why not the first of Tishri? ”
