The Hebrew calendar’s seventh month, the month of Rosh Hashanah, is Tishrei.
Tishrei is the seventh month when months are counted from Nisan, the spring month associated with Passover and the Exodus. Rosh Hashanah begins on the first day of Tishrei, so the festival is both the start of the Hebrew civil year and the opening of the seventh month in the religious sequence.
This apparent contradiction reflects the Hebrew calendar’s multiple year systems. Nisan is treated as the first month for counting the months and dating festivals, while Tishrei begins the calendar year used for ordinary years, sabbatical cycles, jubilees, and many legal documents. Rosh Hashanah therefore falls at the beginning of a new year even though Tishrei is month seven.
Tishrei is a particularly festival-rich month. Rosh Hashanah occurs on days 1–2, Yom Kippur on the 10th, and Sukkot begins on the 15th. The month has 30 days and generally falls in September or October on the Gregorian calendar. Its name is Babylonian in origin; the biblical text also refers to it as Ethanim or simply the seventh month.