Few people know why Jewish tradition added a day to the biblically assigned number for Passover, Shavuot, and Sukkot when the holidays are observed outside of Israel, and why a second day was appended to Rosh Hashanah in both Israel and the diaspora – and those who claim to know the reason behind the additions may be mistaken.
The generally accepted belief is that the tradition started after the Judeans returned to Judea in 538 B.C.E. This return followed some fifty years of exile in Babylonia as a result of the destruction of the First Temple. A short synopsis of the history of Judaism until 538 B.C.E. will put this date into perspective. We will then offer a new idea explaining the origin of the added day.
- What do we know about how the biblical New Moon was celebrated during the reign of King Saul, around 1000 B.C.E.?
- When was an additional day added to the observances of the New Moon?
- What did the Bible require on the seventh New Moon, Yom Teruah, currently called Rosh Hashanah or the New Year holiday?
- What effect did the adding of a day to the New Moon have upon Yom Teruah?
- How did the rivalry between the Judeans and the Samaritans affect the holidays?
- What happened to the New Moon ceremony when the Second Temple was destroyed in 70 C.E.?
- Why is Rosh Chodesh (the New Month) observed for an extra day in modern times when we know by scientific calculations when the new moon appears?
- Why is an extra day added to the Rosh Chodesh observances only when the prior month has thirty days?
- Why is the extra non-biblical day of holiday added to Rosh Hashanah treated differently than the additional days attached to the other holidays? Why are the two days of Rosh Hashanah called yoma arikhta, “one long day”?
The History of Jewry from the Days of Moses until 538 B.C.E.
Scholars date the Israelite Exodus from Egypt under Moses’ leadership to approximately 1250 B.C.E. After forty years of desert wandering, the Israelites entered and conquered parts of Canaan, later called Israel, where they lived under tribal leadership rather than as a single united nation. The first king who remerged the tribes was Saul, who ascended his throne before 1000 B.C.E. David succeeded him, and his son Solomon succeeded him. Solomon built the first permanent Temple. Until his time, the Israelites worshipped either at the Tabernacle that was built by Moses or at local sanctuaries, called bamot.
When Solomon died, his son Rehoboam attempted to retain the united kingdom, but was unsuccessful. Ten of the twelve tribes disbanded and formed their own nation in the north, which they called Israel. Two tribes remained under Rehoboam’s rule in the south in what was called Judea, since the primary tribe was Judah. The name Judeans was later shortened to Jews.
Following the destruction of the northern country of Israel by the Assyrians in 722 B.C.E., virtually all of the Israelites were led into exile. Neither the Bible nor secular history records what happened to them. They were probably absorbed into other cultures; some may have moved to Judea in the south. Today, they are referred to as the “ten lost tribes.”
The Babylonians demolished Judea and Solomon’s Temple in 586 B.C.E., and most of the Judeans were banished to Babylon. In 538 B.C.E. – generally accepted as the period when adding days to most holidays first began – the Judeans were permitted to return to Judea. Some, but not all, returned.
When the Judeans reentered Judea, they discovered a group of people, called Samaritans, inhabiting the nearby area. The origin of these people is debated by both secular and religious scholars. They may have been placed in the land by the Assyrians after they defeated Israel and exiled most of its populace in 722 B.C.E. It is possible that these non-Israelite people integrated with some of the remaining Israelites. The Samaritans adopted some of the religious practices of the ancient Israelite rites but mixed them with paganism. However, the returning ex-exiles, the true Judeans, refused to accept them as co-religionists, and this resulted in centuries of strife between the two groups.
The Problem of Informing the Babylonian Judeans of the First Day of the Month
The returnees were faced with a religious quandary. Judaism relies on a lunar calendar for the dates of its holidays and its adherents must know when each month begins so that they may observe the holidays on the proper days. The system that existed at that time for setting the date of the new moon raised a problem; the date was set in Judea, and the Judeans then had to inform the majority of their brothers and sisters who remained in Babylon when a new month had been established.
The system at that time, one that undoubtedly began even before the days of Moses, was to determine the first day of a month by the testimony of witnesses in a judicial-like proceeding. The witnesses would swear that they had seen the first sliver of the moon. The judges or elders would examine the witnesses and decide if their testimony was true. These people would then establish the day that the moon was first seen as the first day of the month.
The early Israelites knew that the lunar month was approximately twenty-nine and a half days long. Thus, the new month would begin on one of two days, either the thirtieth day after the start of the prior month or the thirty-first. As a result, each month was either twenty-nine or thirty days long.
The Israelites knew how to calculate when the first moon sliver would appear. They had lived among the Egyptians for centuries, first in comparative wealth when Joseph was second to Pharaoh and for some years thereafter, and later under abject slavery. The Egyptians knew how to make calendar calculations. Yet, tradition, as usual, won out. Probably because they had relied on witnesses to establish the month’s onset for so many generations, the Israelites did not want to deviate from their ancestral practice and use the scientific non-Israelite Egyptian calculations. It was not until about the fourth century of the Common Era, during a period of intense persecution, that the ancient witness-oriented system was abandoned in favor of the scientific calculations.
Fire Signals and Samaritan Interference
The following is the generally accepted view explaining why an extra day was added to holidays outside of Israel and to Rosh Hashanah in Israel.
In ancient times, before the introduction of the scientific calendar, the Israelites and Judeans had a formal procedure for announcing the new month to the people. As we said, a court or elders proclaimed the first day of the month after witnesses came and swore that they had seen the first sliver of the moon; but, after entry into Canaan, the Israelites felt that this court or deciding body had to be in Canaan/Israel.
Since only a court/deciding body in Israel could announce the first day of the month, how could the Judeans of 538 B.C.E. notify their brethren in Babylon that the court/deciding body had decided on the day of the new month? This was an important question because the holidays had to be celebrated on the proper date.
An ingenious solution was suggested and implemented. When a decision was reached in Israel concerning the first date of the month, the news was dispatched to Babylon by fire signals from one mountaintop to another. The entire process was completed in hours.
However, a problem arose. The Samaritans, who felt both insulted and excluded by the Judeans, took revenge by doing everything they could conceive of to mortify them. One of their acts was to send fire signals on the wrong day so that the Babylonian Judeans observed the holidays improperly.
The fire signal was no longer a suitable solution, so the Judeans developed a new procedure. They decided that Jews in Judea, in the relatively small area that allowed timely notification of the first day of the month, would continue to observe holidays based on the day established by the appropriate people. However, their co-religionists outside of Judea, who could not be informed of the decision on time, would observe the holidays for an extra day, since the lunar month is twenty-nine and a half days long and the new month began on one of two days. Thus, by celebrating the holidays for an extra day, they would certainly fulfill the biblical obligation correctly on one of the two days.
The Judeans also decided at that time that Rosh Hashanah would be observed even in Judea for two days since it occurred on the first of the month and there was insufficient time to notify even the Judeans in the small area. For example, if the responsible people did not finish interviewing the witnesses and did not proclaim the first day of Tishrei until midday, even the Judeans who lived nearby would have failed to observe half of the holiday and those who lived miles away may have missed the observance entirely. They also resolved that the fast of Yom Kippur should be limited to the biblically mandated single day even outside of Judea, because they knew that it was extremely difficult, if not impossible, for most people to fast for more than a single day.
This is the generally accepted notion as to the origin of the added day of holidays. The following is an original idea by the author of this article. It accepts the history sketched above, but places the original idea for an added day some five hundred years earlier.
Chodesh – The New Moon – Observances in the Bible
The generally accepted view of this issue has rarely been contested. However, an alternate view, equally or more plausible and well grounded in Scripture, should be examined. The current practice of adding an additional day to holidays celebrated outside of Israel and the doubling of the single day of Rosh Hashanah to two days even in Israel probably did not begin in 538 B.C.E., as commonly supposed, but some five hundred years earlier. It most likely began because of difficulties associated with the celebration of the New Moon, not the celebration of the other holidays as is commonly supposed.
Numbers 28:11 mandates special sacrifices to be brought on every Chodesh. These consist of a burnt offering of two bullocks and seven he-lambs, a guilt offering of a he-goat, a meal offering, and oil, flour, and wine.
The Italian exegete, philosopher, and physician Obadiah Sforno notes that while the only biblical observance for the new moon was the sacrifices, I Samuel 20 makes it clear that the Israelites added other customs to enhance the celebrations. I Samuel 20:19 indicates that the day prior to the New Moon was called “the day of work,” thereby indicating that on Chodesh people did not work. Additionally, I Samuel relates that Saul and his court were celebrating the new moon with a feast, and David also notes that he was attending a family feast. The feast may have been what all Israelites did at that time to celebrate Chodesh.
The story of Saul’s feast can reveal to us how and when the extra day was added to holidays, but before we analyze it, we need to understand something about the day that the Bible names Yom Teruah, called the New Year holiday or Rosh Hashanah, in post-biblical literature.
The Biblical Requirements for Yom Teruah, Later Called Rosh Hashanah
Numbers 29 outlines the religious requirements for Yom Teruah. The first day of the seventh month was a day of consecration; a sound/shouting was made (explained by the rabbis as the blowing of a shofar) and no servile work was permitted. There were several sacrifices: a burnt offering of a bullock, a ram, and seven he-lambs; a guilt offering of a he-goat; as well as meal offerings and oil. This was “beside the burnt offering of the Chodesh [New Moon].” In Leviticus 23:24 the day is called Yom Zikhron Teruah, “the day in which there is remembrance through a sound/ shouting.”
The significance of Yom Teruah in the Bible is that it is the seventh month. Its biblical practices are similar to those of every Chodesh (New Month) with certain additions to highlight that it is the seventh month. Just as the seventh day, the seventh year, and the seventh seventh year are significant, and the holidays of Passover and Sukkot consist of seven days each, so, too, the seventh month has special importance and meaning.
How Did King Saul Celebrate the New Month?
Around 1000 B.C.E., King Saul began to suspect that David, a charismatic military officer whom the people praised for his exploits against the Philistine enemy, was trying to usurp his kingdom. He tried to kill David but was unsuccessful. Jonathan, Saul’s son, realized that David would probably succeed his father, but was not bothered because he loved David. I Samuel 20 relates a discussion between David and Jonathan about whether Saul still intended to kill David. They devised a test to see how Saul would react if David did not attend the New Moon celebration, for “tomorrow is the New Moon.” Ultimately, they saw that Saul reacted badly.
Several statements made during Jonathan and David’s discussion raise questions and lead us to conclude that as early as 1000 B.C.E. the Israelites occasionally added a day to the New Moon festivities and celebrated the New Moon for two rather than a single day.
First, we remember that during Saul’s reign and for a long time afterwards the new moon was identified only after witnesses swore that they had seen the first sliver of the moon and elders or a court declared the day as the New Moon. Therefore, how could David in verse 18 and Jonathan in verse 5 say, “tomorrow is the New Moon”? As stated above, since the moon cycle is twenty-nine and a half days, the new month would begin on one of two days. Neither David nor Jonathan could know that the next day would be the New Moon until the witnesses appeared the following evening and the elders or court accepted their testimony.
Second, we need to recall that the Bible states that the new moon is celebrated for a single day. Why then does the book of Samuel tell us that Saul and his entourage observed it for two days?
The Requirement to Offer Timely Sacrifices on the New Moon Prompted the Adding of the Day to Chodesh
Once we take into account that (1) the Bible mandated the offering of sacrifices on the day of the New Moon, (2) the New Moon was established after the testimony of witnesses and a decision by elders or a court, (3) it was possible that the Israelites would not hear the decision until it was too late to bring the sacrifices at the proper time, and (4) the Israelites wanted to observe the biblical sacrificial mandate and their own custom not to work on the day of the new moon and to celebrate it festively, we can readily understand that they must have initiated the practice of adding an extra day to assure that they could bring the biblically required sacrifices and observe the day as they should.
It thus appears that they might have done the following: Since they knew that the new month would begin on one of two days, they ceased work, brought the sacrifices, and engaged in festivities on the first of these two possible days of the new moon. If witnesses came later, said that they saw the moon and that this was the first day of the month, and elders or a court accepted their testimony, then they knew that they did all they should have properly.
When the witnesses came on this first day, they did not celebrate the new moon on the next day because they had no need to do so. If no witnesses appeared, they also celebrated the next day as Chodesh. It was in this way that they were able to fulfill the biblical commandments regarding Chodesh as well as the celebrations that they added for the day.
The adding of an extra day to the New Moon also explains how the Israelites were able to observe the day properly when the heavens were overcast and the moon was not visible. They would observe the rituals of the day on the twenty-ninth as well as on the thirtieth if no witnesses appeared on the twenty-ninth day of the month.
Thus, David and Jonathan would know the day of the celebration for the New Moon before it was announced, because the day following their conversation was set aside for the celebration of the New Moon even before the witnesses testified.
This is also why we read that Saul and his court celebrated a second day of Chodesh, despite the Bible only requiring a single day; the witnesses had not appeared on the first day, the twenty-ninth day of the month.
Thus, it was the desire to celebrate the New Moon properly that caused the beginning of the practice of adding a day to the festivities. How did this day added to Chodesh affect Yom Teruah and other holidays?
Lengthening Chodesh Lengthened Yom Teruah
Since Yom Teruah is the first day of a month, an extra day was undoubtedly added to its celebration for the same reason that it was added to an ordinary Chodesh. Both the extra day for Chodesh and Yom Teruah were most certainly appended before the era of King Saul, perhaps as early as the time of Joshua, when the tribes were no longer centralized in the desert, but dispersed throughout Canaan, and communication was difficult and time-consuming.
It is likely that no additional day was attached to the other holidays during this early period since all the other holidays occurred later in the month, on a date when the people would already have been notified as to the established first day of the month. These holidays presented no problem until the Judeans separated into two groups, one in Judea and the other in distant Babylonia, and the Samaritans created a communication difficulty by interfering with the fire signals.
In short, it is very possible that the need for an extra day began before 1000 B.C.E. and was implemented initially only for Chodesh and Yom Teruah. When the Samaritans made it impossible to communicate the onset of the month in a timely fashion around 538 B.C.E., the centuries-old idea was expanded and applied to other holidays.
Why is Rosh Hashanah Treated Differently Today Than Other Holidays?
The Bible does not indicate the date on which the world was created. Different views existed during the post-biblical period. Some rabbis suggested that the world was created in the spring month Nissan, while others opted for the fall month Tishrei. When the latter idea was accepted by the people, they began to call Yom Teruah, which by that time was two days, the first and second days of Tishrei, the New Year, Rosh Hashanah.
The rabbis called Rosh Hashanah yoma arikhta, “a single long day,” and certain halakhic problems arose because they considered the two days a single long day. One such dilemma was whether the blessing of Shehecheyanu – which is only said for something new – should be said on the second day. If the two days of Rosh Hashanah are considered a single long day, Shehecheyanu should not be said on the second day. The decision was made to compromise: the prayer of Shehecheyanu would be recited on the second day, but over a new fruit, one that had not been eaten during the prior year.
This prayer issue aside, why are the two days of Rosh Hashanah treated differently than the two days of other holidays? Or, to put the question differently, why is the extra day added to Rosh Hashanah treated differently than the extra days added to other holidays?
Now that we understand that the observance of Rosh Hashanah for two days began at least five hundred years before a day was added to other festivals, we can see why Jews wanted to treat Rosh Hashanah differently. Since the Bible mandated the observance of Yom Teruah/Rosh Hashanah for only one day, and the practice of celebrating it for two days is more ancient than the added day to other festivals, it was called “a single long day” to highlight that Rosh Hashanah is different than the other holidays because it has the more ancient two-day observance. It is also possible that the name yoma arikhta was given to the holiday in ancient times before an extra day was attached to the other holidays in order to emphasize that since the Bible mandates that it be observed for one day, even after a day was added Rosh Hashanah was considered one long day and therefore not longer than the biblical mandate. When a day was added to the other holidays, they were not called “a single long day” since that title was already given to Rosh Hashanah.
The Observance of Chodesh after the Destruction of the Second Temple
When the Second Temple was destroyed in 70 C.E. and sacrifices were discontinued, there was no further need for a second day of Chodesh, because its biblical practices focused on sacrifices. However, since the people considered prayer a replacement for sacrifices and since the added day was an ingrained traditional Jewish practice, Jews felt that they should not discontinue the way their ancestors celebrated Chodesh. This is also the reason that Jews did not discontinue the practice of the extra day added to other holidays.
When the calendar was established around the fourth century C.E. and witnesses were no longer used, an extra day of Chodesh was only added to months in which the prior month had thirty days. Why was the extra day added only when the prior month lasted thirty days? Since Chodesh could only occur on one of two days, the thirtieth or thirty-first day after the first day of the prior month, the thirtieth and the first days are celebrated as Chodesh, as a remnant and reminder of the ancient practice. However, when the month ends on the twenty-ninth day, the first day of the next month is certainly Chodesh and the second day of the month is certainly not Chodesh and is not treated as such.
Most Jews suppose that the extra day attached to Rosh Hashanah, Passover, Shavuot, and Sukkot was initiated around 538 B.C.E. by the Judeans in Judea at the end of the Babylonian exile. They are certain that the day was added because the Judeans were unable to notify their brethren in Babylon that their court established the first day of the month after witnesses testified to seeing the first sliver of the moon, due to the interference of the Samaritans. We presented the idea that the practice actually began about five hundred years earlier, during or more likely before the days of King Saul. We proved our conclusion using the description of the New Moon celebration described in I Samuel 20. We saw that the text clearly refers to a two-day New Moon celebration. This understanding might appear to be a radical one, as it flies in the face of the traditional belief about the New Moon and the Jewish calendar. However, a straightforward reading of the text of I Samuel clearly presents this approach as the more rational and historically correct.
 The Spanish rationalist, Bible commentator, and philosopher Abraham Ibn Ezra and the French mystically-minded Bible commentator Chizkiyah ben Manoach Chazkuni explain that the Bible only calls the first day of the month of Nissan Rosh Chodesh, and that the term Rosh Chodesh means “the first of the months,” because the Bible considers Nissan the first month of the year. The Bible calls all other first days of the months simply Chodesh, as indicated in Numbers 28:14 and in I Samuel 20. They point out that Numbers 28:14 applies the Nissan obligation to the first day of every other month: “This is [also] the burnt offering of every Chodesh throughout the months of the year.” The name Rosh Chodesh, however, was used in post-biblical days as the name of the first day of every month.
 Targum Jonathan translated “day of work” as yoma d’chol, “a week-day,” thereby indicating that Chodesh was a special day of rest.
 The Encyclopedia Mikra’it, Zevach, does not understand David’s feast as his family’s celebration of the new moon, as we contend, but as a yearly family affair, a kind of Thanksgiving Day. It adds that the book of Samuel shows that this family get-together was always observed on the day of the new moon. It does not explain why the new moon day was used to celebrate this Thanksgiving.
 What is remembered? Ibn Ezra and Rashbam state that the Jew was encouraged to remember God. Later Jewish thinkers suggested that the Jews were encouraged to remember their past misdeeds and to decide not to repeat them and that, secondly, God remembered to treat Jews well.
 The names of the months are post-biblical and were copied from the Babylonian practice.