Hebrew Hours & Calendar

The Hebrew calendar is a lunisolar calendar, or “fixed lunar year,” based on twelve lunar months of twenty-nine or thirty days, with an intercalary lunar month added seven times every nineteen years (once every two to three years) to synchronize the twelve lunar cycles with the slightly longer solar year. Each Hebrew lunar month starts with the new moon. In laymen’s terms the time and calendar is based on day, night, and the seasons of the earth. I couldn’t imagine a better calendar than the calendar of God’s Kingdom.

The principles of the Hebrew calendar are found in the Torah, which contains several calendar-related commandments, including God’s commandment during the Exodus from Egypt to fix the month of Nisan as the first month of the year (Exodus 12:2).

Hebrew Hours

The Hebrew day and hours have no fixed length. The Hebrew day is modeled after the scripture reference “…there was evening and there was morning…” found in the following scriptures in the story of Creation: Gen 1:5, Gen 1:8, Gen 1:13, Gen 1:19, Gen 1:23, Gen 1:31 and Gen 2.2.

The Hebrew Day is based on twelve hours of Daylight and twelve hours of Night. Every day has twelve hours and every night has twelve hours. Each day begins with sunrise and ends with sunset and each hour is determined by the amount of daylight there is, hence that no day is fixed and hours are different each day.

Hebrew Days & Weeks

The Hebrew calendar follows a seven-day weekly cycle, which runs concurrently but independently of the monthly and annual cycles. The names for the days of the week are simply the day number within the week. In Hebrew, these names may be abbreviated using the numerical value of the Hebrew letters, for example יום א׳ (Day 1, or Yom Rishon (Hebrew: יום ראשון‎):

Yom Rishon (יום ראשון), abbreviated יום א׳ = “first day” = Sunday
Yom Sheni (יום שני), abbr. יום ב׳ = “second day” = Monday
Yom Shlishi (יום שלישי), abbr. יום ג׳ = “third day” = Tuesday
Yom Reviʻi (יום רבעי), abbr. יום ד׳ = “fourth day” = Wednesday
Yom Chamishi (יום חמישי), abbr. יום ה׳ = “fifth day” = Thursday
Yom Shishi (יום ששי), abbr. יום ו׳ = “sixth day” = Friday
Yom Shabbat (יום שבת or more usually שבת – Shabbat), abbr. יום ש׳ = “Sabbath day (Rest day)” = Saturday

The names of the days of the week are modeled on the seven days mentioned in the Creation story. For example, Genesis 1:5 “… And there was evening and there was morning, one day”. “One day” also translates to “first day” or “day one”. Similarly, see Genesis 1:8, 1:13, 1:19, 1:23, 1:31 and 2.2.

The Jewish Shabbat has a special place in the Jewish weekly cycle. There are many special rules which relate to the Shabbat, discussed more fully in the Talmudic tractate “Shabbat”.

In Hebrew, the word “Shabbat” (שַׁבָּת) can also mean “(Talmudic) week”, so that in ritual liturgy a phrase like “Yom Reviʻi bəShabbat” means “the fourth day in the week”.

Hebrew Months

Numbers 10:10 stresses the importance of the new moon and consequently lunar months, “… in your new moons, ye shall blow with the trumpets over your burnt-offerings,”. Similarly in Numbers 28:11.

Biblical references to the pre-Jewish calendar include ten months identified by number rather than by name. In parts of the Torah portion Noach (Noah) (specifically, Gen 7:11, Gen 8:4-5, Gen 8:13-14) it is implied that the months are thirty days long. There is no indication as to the total number of months in the annual cycle.

In the parts of the Tanakh (the Hebrew Bible) prior to the Babylonian exile, only four months are named: Aviv (Exodus 12:2, Exodus 13:4, Exodus 23:15, Exodus 34:18, Deut. 16:1) (first; literally “spring”, which originally probably meant “the ripening of barley”); Ziv (1 Kings 6:1, 1 Kings 6:37) (second; literally “light”); Ethanim (1 Kings 8:2) (seventh; literally “strong” in plural, perhaps referring to strong rains); and Bul (1 Kings 6:38) (eighth). All of these are Canaanite names, and at least two are Phoenician (Northern Canaanite).[citation needed]

According to the Book of Exodus, the first commandment the Jewish people received as a nation was to determine the new moon: Exodus 12:2 states, “This month [Nisan] is for you the first of months.” Deut 16:1 refers to a specific month: “Observe the month of Aviv (HE: spring), and keep the passover unto the LORD thy God; for in the month of Aviv the LORD thy God brought thee forth out of Egypt by night.”

During the Babylonian exile, which started in 586 BCE, Jews adopted Babylonian names for the months, which are still in use. The Babylonian calendar also used a lunisolar calendar, derived from the Sumerian calendar, which was similar in structure to the Hebrew one.

Hebrew names and romanized transliteration may somewhat differ, as they do for חשוון / Marheshvan or כסלו / Kislev: the Hebrew words shown here are those commonly indicated e.g. in newspapers. The Syrian calendar used in the Levant countries shares many of the same names for months as the Hebrew calendar, such as Nisan, Iyyar, Tammuz, Ab, Elul, Tishri, and Adar.

Hebrew Years

An ordinary (non-leap) year has 353, 354, or 355 days. A leap year has 383, 384, or 385 days. The three lengths of the years are termed, “deficient”, “regular”, and “complete”, respectively.

An ordinary year has 12 months, a leap year has 13 months.

Every month starts (approximately) on the day of a new moon.

The months and their lengths are:

The month Adar I is only present in leap years. In non-leap years Adar II is simply called “Adar”.

Note that in a regular year the numbers 30 and 29 alternate; a complete year is created by adding a day to Heshvan, whereas a deficient year is created by removing a day from Kislev.

The alteration of 30 and 29 ensures that when the year starts with a new moon, so does each month.