Biblical Month

NOTE: Some of the Jewish traditions associated with the Biblical Calendar are steeped in Kabbalah beliefs.  More information on the Kabbalah aspects of the Biblical Calendar can be found here at Chabad.org.

Names of the Months

According to the Torah, the months of the year do not have names, but rather, are simply numbered.  The only exception to this was the 1st month of the year which was also referred to as the month of “Aviv”, which means “fresh barley ears”.  This was not the name of the month, but rather, a description given to that month due to it being the month when the fresh ears of barley would sprout and be seen.  This description helped the Hebrew people to know when the year was starting.

After their exile to Babylon, the Jewish people adopted Babylonian names for the months of the year.

• 1st Month – Nisan (generally occurring during March and April on a Gregorian calendar)
• 2nd Month – Iyar (generally occurring during April and May on a Gregorian calendar)
• 3rd Month – Sivan (generally occurring during May and June on a Gregorian calendar)
• 4th Month – Tammuz (generally occurring during June and July on a Gregorian calendar)
• 5th Month – Menachem Av (generally occurring during July and August on a Gregorian calendar)
• 6th Month – Elul (generally occurring during August and September on a Gregorian calendar)
• 7th Month – Tishrei (generally occurring during September and October on a Gregorian calendar)
• 8th Month – Mar Cheshvan (generally occurring during October and November on a Gregorian calendar)
• 9th Month – Kislev (generally occurring during November and December on a Gregorian calendar)
• 10th Month – Tevet (generally occurring during December and January on a Gregorian calendar)
• 11th Month – Shevat (generally occurring during January and February on a Gregorian calendar)
• 12th Month – Adar (generally occurring during February and March on a Gregorian calendar)

Jewish Leap Year

12 lunar months add up to a total of 354 days, which is slightly more than 11 days short of a solar cycle which lasts 365.25 days.  To help keep the lunar-based Jewish year in alignment with the solar cycle and seasons, the Jewish “Leap Year” was established. 

This Jewish Leap Year occurs 7 times during each 19-year cycle.  The Leap Year has 13 months instead of 12 months.  During the Jewish Leap Year, the 12th month becomes Adar I and the 13th month becomes Adar II.

Sanctifying the Chodesh (Start of the New Month)

Originally, the Hebrew people entrusted the Sanhedrin (rabbinical supreme court) to decide when each month officially started.  Visual observation of the new crescent moon would be the proof used, and then the Sanhedrin would sanctify the start of the new month.  The Sanhedrin would also decide whether the new month would be a 29-day month or a 30-day month, depending on when the sighting of the crescent moon took place.

On the 30th day of every month,7 the Sanhedrin would “open for business” in a large courtyard in Jerusalem called Beit Ya’azek. Witnesses who claimed to have seen the new moon on the previous night would come to give their testimony and be cross-examined.

At the end of each month (the 30th day) the Sanhedrin would meet in a large courtyard in Jerusalem called Beit Ya’azek. Here, witnesses who claimed to have seen the new moon on the previous night (at sunset) could come and give their testimony. The Sanhedrin required 2 witnesses to establish the start of the new month. As such, the witnesses would individually need to answer a series of questions…

• In which direction was it in relation to the sun?
• Was it to the north or south?
• How high in the sky did the moon appear to be?
• In which direction were the crescent’s tips facing?
• How wide was it?

This questioning was done privately with each witness being separated from the other, with the eldest witness questioned first.  The Sanhedrin members, being schooled in astronomy, would be able to determine if the witnesses were being truthful or not.  If the witnesses’ testimonies agreed and were found to be truthful, the day was declared “mekudash” (sanctified). The Sanhedrin would cry out “Mekudash!” and the people would respond “Mekudash! Mekudash!”.

Bonfires were then lit on mountain tops to alert all the people of the land that the new month had been sanctified. 

In later years, messengers were dispatched to outlying communities to relay the information, to avoid confusion created by the Samaritans who tried to manipulate the calendar by purposely lighting fires on the wrong days.  This created delays in announcing the start of the new month to Jewish people further away from Jerusalem… which eventually lead to the tradition of most holy days (mo’edim) being celebrated for 2 days by Jewish people in the diaspora, to make up for starting their months a day late.

If no witnesses came forth on the 30th day to declare the sighting of the new moon, the Sanhedrin would then retroactively declare the previous month to be a “30-day month” and the new month would start the following day.

The Hillel II Calendar

In the 4th century, the Sanhedrin was disbanded and the Jewish sage Hillel II and his rabbinical court established the perpetual calendar used by the Jewish people today.

The perpetual calendar was purposely set up to ensure that Yom Teruah (Day of Trumpets, otherwise known as Rosh Hashanah, the “Jewish New Year”) would never take place on a Sunday, Wednesday or Friday.

To do this, the following calendar was put into play:

• 1st Month – Nisan – 30 Days
• 2nd Month – Iyar – 29 Days
• 3rd Month – Sivan – 30 Days
• 4th Month – Tammuz – 29 Days
• 5th Month – Menachem Av – 30 Days
• 6th Month – Elul – 29 Days
• 7th Month – Tishrei – 30 Days
• 8th Month – Mar Cheshvan – 29 or 30 Days
• 9th Month – Kislev – 29 or 30 Days
• 10th Month – Tevet – 29 Days
• 11th Month – Shevat – 30 Days
• 12th Month – Adar – 29 Days (during leap years, Adar I has 30 Days and Adar II has 29 Days)

Hillel II also established rules to determine the number of days for the 8th and 9th months each year.  These rules would allow for 1 of 3 options…

• Both months can have 29 days, making the year “chaser” (lacking)
• Both months can have 30 days, making the year “malei” (whole)
• The 8th month is 29 days and the 9th month is 30 days, making the year “k’sidran” (regular)

The calendar established by Hillel II is considered “sanctified” by the Jewish people, until the return of the Messiah (Yeshua).

More details on the Jewish traditions surrounding the Biblical Month can be found here at Chabad.org.