The Jewish Calendar

What is a "Kallah month"? It refers to a practice in the Babylonian Yeshivos, when large groups of students attended special intensive study sessions during the months of Adar and Ellul.

Why don't the Jewish holidays occur on the same secular dates every year? The Jewish year is usually 12 lunar months long, but 12 lunar months add up to only 354 days. To keep the Jewish year in step with…

Why does the Torah (in Lev. Ch. 23) refer only to the festivals of the seventh month as "sabbaths"? The same types of work are prohibited on all the holidays; the Torah defines it, in connection with Passover, in Ex.12:16.…

When does the day begin? The Jewish day begins at sundown. The Biblical source for this is Genesis Ch.1, where the Days of Creation are counted using the wording "It was evening and it was morning, one day" (etc.).

When the Torah mentions a period of days, are they complete or partial days? There’s a Talmudic principle that “part of a day is like a day” (Pesachim 4a); this means that part of the first or last day of…

How do the Jews measure time? An hour is defined as 1/12 of a day; thus the length of an hour varies with the seasons and with latitude. To define periods of time more precisely, an hour is divided into…

How is the Jewish calendar fixed? Fixing the calendar is the responsibility of the Sanhedrin (the highest Jewish court); today we use rules that the Sanhedrin formulated about 1500 years ago. Since the calendar underlies all the commandments that have…

What is the meaning of the name of the month MarCheshvan? According to the Encyclopedia Judaica (vol.11 cols. 971-2), the word “marcheshvan” is believed to be etymologically related to the Assyrian “arahsammu”, “eighth month”. In the Bible (1 Kings 6:38)…

Where did the names of the Jewish months come from? The names that we use nowadays come from Bablyonia (Talmud Yerushalmi Rosh Ha-Shanah 1:2); in Biblical times the months had other names. Only four of the original Hebrew names of…