For six months, the messengers go forth: for Nissan, because of Pesach; for Av, because of the Fast; for Elul, because of Rosh Hashanah; for Tishrei, because of the [proper] determination of the holidays; for Kislev, because of Chanukah; for Adar, because of Purim. And when the Temple was in existence, they went forth also for Iyar, because of [the] minor Pesach.

For two months, the witnesses may desecrate the Sabbath: for Nissan, and for Tishrei, for on them the messengers go forth to Syria, and on them they fix the holy days. And when the Temple was in existence, they desecrated even for all of them because of the determination [of the time] of the sacrifice.