The Longest Year

Since this is a leap year, in which we add an extra month for Adar, this year has 385 days – making it the longest year that our current Jewish calendar can have. Therefore, I am presenting:

The Longest Year

“Thirty days hath September / April, June and November.” If we were to adapt this poem to, l’havdil, our current, standardized Jewish calendar, we would say that thirty days hath Tishrei, Shvat, Nissan, Sivan, Av, and sometimes Cheshvan1 and Kislev. But the idea of having a standardized Jewish calendar seems to run counter to several mishnayos in Rosh HaShanah. In those mishnayos, we see that whether a specific month has 29 days or 30 days depends on whether witnesses saw the new moon and testified in beis din early enough to declare the 30th day Rosh Chodesh (that is, the first day of the next month). In addition, the Gemara2 states that at times Elul could be 30 days long — which cannot happen in our calendar.

How did our empirical calendar become so rigid and predictable? The Torah (Shemos 12:2) commands the main beis din of the Jewish people (also known as the Sanhedrin), or a beis din specially appointed by them, to declare Rosh Chodesh upon accepting the testimony of witnesses who observed the new moon.3 The purpose of having eyewitnesses was not to notify the beis din that the moon had appeared; the beis din had extensive knowledge of astronomy and could predict exactly when and where the new moon would appear and what size and shape it would be.4 The Torah obligated the beis din to wait for witnesses, however, and they could only rule on whether the 30th day would be the last day of the old month or would become the first day of a new month, based on testimony. If no witnesses to the new moon arrived on the 30th day, then the 31st day became Rosh Chodesh, regardless of the astronomic calculations (Mishnah Rosh HaShanah 24a). At that point in Jewish history, any month could be either 29 or 30 days.

The Torah also commands us that Pesach must always fall during the spring (Devarim 16:1). This seemingly innocuous mitzvah actually requires considerable manipulation of the calendar, since months, derived from the word moon, are determined by the length of time from one new moon to the next, which is a bit more than 29½ days. A lunar year is, or more accurately, twelve lunar months are, almost exactly 354 days. The seasons of the year, on the other hand, are calculated according to the solar year, because seasons change based on where the sun’s most direct rays strike the earth. This varies daily, as the most direct rays move from the north Tropic of Cancer to the south Tropic of Capricorn and back again. A solar year is a bit less than 365¼ days, and is based on the length of time it takes the earth to rotate around the sun. Since Pesach must always take place during the spring, the calendar cannot be twelve lunar months every year, because over time, the eleven-day discrepancy between the lunar and solar years would cause Pesach to wander through the solar year and occur in all seasons.5

The Two “Other” Calendars

There are four calendars commonly in use in the world today, two of which make no attempt to resolve the discrepancy between solar and lunar years. The most common secular calendar (the Gregorian or Western calendar) is based solely on the sun. Although the year is nominally broken into twelve months, the use of the word “months” here is a significant departure from its original meaning. In the Gregorian calendar, months have no relationship to the cycles of the moon. Most secular months have 31 days, while the lunar cycle is only about 29½ days, and even secular months that have 30 days do not relate to any phase or change in the moon. Similarly, the length of February as a month of either 28 or 29 days has nothing to do with the moon. Thus, although the word month should correspond to the moon, the Gregorian calendar is purely a solar one, with the borrowed term, “month,” given a meaning detached from its origin.

Another calendar that is seeing increased use today is the Muslim one, which is purely a lunar calendar of twelve lunar months, some 29 days and some 30. In truth, a pure lunar calendar has no real “year,” since a year is based on the relative locations of the sun and the Earth and the resultant seasons, while a lunar “year” of twelve lunar months completely ignores seasons. The word “year” is used in the Muslim sense only as a basis for counting longer periods of time, but has no relationship to the sun. In fact, the Muslim “year” is only 354 or 355 days long — almost eleven days shorter than a solar year. Therefore, a Muslim who tells you that he is 65 years old is really closer to 63 according to a solar year count. He has counted 65 years, each of which is at least ten days shorter than a real (solar) year. (I trust that Guinness takes these factors into account when computing world records for longevity and the like.)

The Muslim year “wanders” its way through the seasons, taking 33 years until a specific month returns to the exact same point in the solar year in the previous cycle. In the interim, that month has visited each of the other seasons for several consecutive years.

13 month years

There are two commonly used calendars whose months are based on the moon, and years are based on the sun. The traditional eastern Asian calendar, usually referred to as the “Chinese Calendar” and the Jewish calendar, both accommodate this by having some years that are thirteen months and others that are twelve. The methods used by these two calendars to decide which month is doubled and when are quite different. Since our articles are on halacha, I will not discuss the details on how the Chinese calendar decides which month to double and when to do so.

The Jewish Calendar

As we have seen, we are commanded to create a calendar that uses the lunar cycle to define the months, but also to keep our months in sync with the seasons, which are dependent on the sun, in order to determine the dates of the Yamim Tovim. The only way to do so is to occasionally add a month, thereby creating a thirteen-month year, to offset the almost eleven-day difference between twelve lunar months and a solar year. The result of this calendar is that although each date does not fall exactly on the same “solar date” every year, it falls within a close range relative to the solar year. Who determined which years have thirteen months?

Under the original system, the main beis din appointed a smaller special beis din to determine whether the year should have an extra month. This special beis din took into consideration:

1) Astronomical data, such as when Pesach will fall out relative to the vernal equinox (the spring day on which day and night are closest to being equal in length).

2) Agricultural data, such as: How ripe is the barley? How large are the newborn lambs and pigeons?

3) Weather: Is the rainy season drawing to a close? Is there a famine?

4) Convenience, or more specifically, the halachic inconvenience of creating a leap year. The shmittah year and the year following were never made into leap years, and the year before shmittah usually was.

5) Infrastructure. For example, the condition of the highways and bridges.

All of these points influenced whether the thirteenth month, the additional Adar, would be added.6 When this system was in place — during a period without interruption from the time of Moshe and Yehoshua until about 300 years after the destruction of the Beis HaMikdash — the main beis din sent written messages notifying outlying communities of the decision to create a leap year, and the reasons for their decision.7

Creation of the “Permanent” Calendar

During the later era of the Talmud, Roman persecution made it impossible to continue declaring Rosh Chodesh based on eyewitness testimony. Thus, Hillel HaNasi (not to be confused with his more illustrious ancestor, the Tanna Hillel, also sometimes called Hillel Hazakein, who lived several hundred years earlier) instituted a calendar based purely on calculation, without human observation of the new moon. Rambam explains that the mitzvah of the Torah is that if it becomes impossible to declare Rosh Chodesh and leap years on the basis of observation, then the beis din should create a permanent calendar.8 Hillel HaNasi’s calendar kept the same basic structure of 29- and 30-day months and twelve- and thirteen-month years, but it was based purely on calculation and not on the variables mentioned above.

When Hillel HaNasi created the new calendar, he incorporated in its calculations several innovations. The two major changes in this new calendar are:

1) A Leap of Fate

Leap years now follow a regular pattern of seven leap years, called me’ubaros, and twelve non-leap years, called peshutos (ordinary), in a nineteen-year cycle. The third, sixth, eighth, eleventh, fourteenth, seventeenth, and nineteenth years of the cycle are always leap years, and the rest are ordinary years. This year, 5779, is the third year of the cycle and thus is a leap year.

2) The Haves vs. the Have-Nots

The length of most months is now fixed. Tishrei, Shvat, Adar Rishon (which exists only in a leap year), Nissan, Sivan, and Av will always have 30 days; Teves, regular Adar (in a common, nonleap year), Adar Sheini (in a leap year), Iyar, Tammuz, and Elul are always 29 days long. The months of Cheshvan and Kislev are the only months that can vary — sometimes they are 29 days and sometimes they are 30 days.9 A year in which both Cheshvan and Kislev have only 29 days is called chaseirah, lacking. If Cheshvan has 29 days and Kislev has 30, the year is considered kesidrah, expected or regular. If both Cheshvan and Kislev have 30 days, the year is called sheleimah, full.10

Both ordinary and leap years can be either chaseiros, kesidran, or sheleimos. Thus, in the new calendar, all ordinary years are either 353 days (if both Cheshvan and Kislev have 29 days), 354 days (if Cheshvan has 29 days and Kislev has 30), or 355 days (if both Cheshvan and Kislev have 30 days). All leap years are either 383 days (if both Cheshvan and Kislev have 29 days); 384 days (if Cheshvan has 29 days and Kislev has 30), or 385 days (if both Cheshvan and Kislev have 30 days). Since Adar Rishon always has 30 days, the addition of an extra month in a leap year always adds exactly thirty days.

(Because the nineteen-year cycle synchronizes the lunar calendar with the solar year, the Hebrew and English dates of births, anniversaries, and other occasions usually coincide on the nineteenth anniversary of the event. If yours is off by a day or two, do not fret. Your recordkeeping is accurate, but the cycle of nineteen years relates only to whether it is a leap year, not to whether the years are of the exact same length. The lengths of Cheshvan and Kislev are determined by other factors, plus the fact that February 29 does not occur every secular year will affect whether your 19th, 38th, 57th, 76th, or 95th Hebrew and secular birthday or anniversary exactly coincide, or whether they are slightly off.)

Revealing Top Secret Information

In order for the new calendar to be established properly, a very carefullyguarded secret had to be revealed. Chazal had always kept secret how one can predict when the new moon is destined to appear, a calculation called the sod ha’ibur. This information had always been kept secret in order to prevent false witnesses from coming forth and testifying that they saw the moon at a time when they knew it could be seen. With the new calendar coming into use, this was no longer a concern. Moreover, people had to know the secret in order to calculate the calendar correctly. The sod ha’ibur is that each new moon appears 29 days, 12 hours, and 793 chalakim or 793/1080 of an hour after the previous new moon.11

Once one knows when the new moon, called the molad, occurred on one Rosh HaShanah, he could add the sod ha’ibur figure either twelve or thirteen times (depending on the number of months that year) and determine the time of the molad in the next year, which is the most important factor in determining the date of the next Rosh HaShanah.

Another factor had also been guarded as a secret: that Rosh HaShanah sometimes takes place not on the day of the molad, but the next available day (see below). In the old system, this happened when the molad fell on the afternoon of Rosh HaShanah and the moon would not be visible in Eretz Yisrael until the next day. When Rosh HaShanah was determined by the observation of witnesses, this information was important not only in determining when Rosh HaShanah falls, but also when interrogating potential witnesses testifying to the appearance of the new moon. Although the new calendar is no longer dependent on witnesses seeing the moon, and so we could conceivably set Rosh HaShanah even in a year when the molad falls during the afternoon, we nevertheless postpone Rosh HaShanah to the following day. Thus, creating the calendar in a way that it could be used required revealing these two secrets, so that a person could determine which day should be Rosh HaShanah in the coming year.

Additional Innovations

Did you ever notice that Yom Kippur never falls on Friday or Sunday? If it did, we would have to observe two consecutive days, both of which have the stringency of Shabbos. Even today we can appreciate the difficulty that this poses, although it was even greater in the era before the discovery of the principles of refrigeration.

When the calendar was based on observation, Yom Kippur did sometimes fall on either Friday or Sunday.12 However, Hillel HaNasi’s new calendar included some innovations that were not part of the earlier calendar. The new calendar does not allow Yom Kippur to fall on either a Sunday or a Friday, thus avoiding the difficulty of having two Shabbos-like days fall consecutively. It also does not allow Hoshana Rabbah to fall on Shabbos, which would cause the cancellation of the hoshanos ceremony.

As long as the calendar was determined on the basis of eyewitness testimony, the halachah favored having Rosh Chodesh fall on its most correct day, over the concerns of having two Shabbos-like days fall consecutively, or canceling the hoshanah ceremony on Hoshanah Rabbah.13 But after eyewitness testimony could no longer be used, and we were going to implement a permanent calendar that fulfilled the mitzvah in a less-preferred way anyway, the halachah then went the other way: it favored keeping Yom Kippur from falling on Friday or Sunday, and keeping Hoshanah Rabbah from falling on Shabbos.

In order to accommodate these innovations, Rosh HaShanah could now fall only on Monday, Tuesday, Thursday, or Shabbos, since if it falls on Sunday, Hoshana Rabbah falls on Shabbos; if Rosh HaShanah falls on Wednesday, Yom Kippur falls on Friday; and if Rosh HaShanah falls on Friday, Yom Kippur falls on Sunday. This would mean that when Rosh HaShanah in the coming year would naturally fall on Sunday, Wednesday, or Friday, an extra day is added to the calendar to make sure that Rosh HaShanah falls on Monday, Thursday, or Shabbos instead.14 This concept of ensuring that Rosh HaShanah not fall on Sunday, Wednesday, or Friday is called

ראש לא אד”ו , lo adu Rosh, meaning that the beginning of the year, Rosh HaShanah, does not fall on א, the first day of the week, Sunday; ד, Wednesday; or ו, Friday. It is predominantly for this reason that there was a need to have Cheshvan and Kislev sometimes 29 days and sometimes 30, in order to make the exact length of the years flexible.

Although adding one day to the year so that Rosh HaShanah will not fall on a Sunday, Wednesday, or Friday seems simple, at times the calculation needs to take additional factors into consideration, as we will see shortly. Since Hillel HaNasi’s calendar did not allow a common year to be longer than 355 days and a leap year to be shorter than 383 days, the only way to avoid this happening is by planning in advance what will happen in the future years, and adjusting the calendar appropriately.

In order to accommodate these various calendar requirements, Hillel HaNasi established four rules, called dechiyos, which, together with the sod ha’ibur calculation and the nineteen-year rotation, form the basis of determining our calendar.15 We’ll use a sample two years calculation of the molad for Rosh HaShanah to explain a dechiyah. A few years ago, the molad calculation for Rosh HaShanah fell on Wednesday evening, and Rosh HaShanah therefore was on Thursday, which is what we would expect. But the following year’s molad fell on Tuesday, less than two hours before the end of the day. Although the molad was on Tuesday, it was too late in the day for this molad to be visible in Eretz Yisrael, and therefore Rosh HaShanah could not occur before Wednesday. However, since Rosh HaShanah cannot fall on a Wednesday, because of the rule of lo adu Rosh, it had to be pushed off to Thursday, or two days after the molad. For this reason, that year had to have an extra day, making it not only a leap year, but also a sheleimah, when both Cheshvan and Kislev have thirty days. This created a year of 385 days, the longest a year can be.16

As mentioned above, although the leap years follow a fixed nineteen-year cycle, whether the year is chaseirah, kesidrah, or sheleimah is determined by the other factors we have noted, and therefore does not follow the nineteen-year pattern. Rather, one first calculates when Rosh HaShanah should fall out based on the sod ha’ibur, then checks the rules of the dechiyos to see what adjustments need to be made, and then determines on which day Rosh HaShanah should fall. As a result, whether the year in question needs to be chaseirah, kesidrah, or sheleimah requires calculating not only that year’s schedule, but also the coming year’s calendar requirements. A result of all these calculations is that although there might seem to be many potential variables used in calculating the years (the day of the week of Rosh HaShanah, whether it is a leap year or ordinary year, and whether the year is chaseirah, kesidrah, or sheleimah), for reasons beyond the scope of this article, there are only seven possible prototype years for an ordinary year, and seven for a leap year.

Each of these fourteen prototype “years” is identified by a three-letter acronym, in which the first letter identifies the day of the week of the first day of Rosh HaShanah; the second letter denotes whether the year is chaseirah, kesidrah, or sheleimah; and the third letter identifies the day of the week of the first day of Pesach. No letter is used to denote whether the year is an ordinary year or a leap year, because this can be calculated by knowing how many days of the week there are between Pesach and Rosh HaShanah. In a common ordinary year that is kesidrah, Pesach falls two days later in the week than Rosh HaShanah. In a leap year, it falls four days later, the two additional days being the extra two days that Adar Rishon, which is thirty days long, adds to the count of the days of the week. Of course, these calculations must be adjusted one day in either direction if the year is chaseirah or sheleimah. Thus, the acronym for this year, 5779, is bais shin zayin בשז – Rosh HaShanah was on a Monday, the year is a sheleimah (both Cheshvan and Kislev had 30 days), and the first day of Pesach is on Shabbos.

 

(Endnotes)

1 Although the correct name of the month is Marcheshvan, we will use the colloquial name, Cheshvan.

2 Rosh HaShanah 19b, 20a.

3 Rambam, Hilchos Kiddush HaChodesh 1:1, 7; 5:1.

4 Ibid. 2:4; Ritva on the Mishnah Rosh HaShanah 18a.

5 Rambam, ibid. 4:1.

6 Sanhedrin 11a–12a.

7 Sanhedrin 11b; Rambam, Hilchos Kiddush HaChodesh 4:17.

8 Ibid. 5:2.

9 Ibid. 8:5.

10 Since Kislev is sometimes 29 days and sometimes 30, the last day of Chanukah can either be on the second or the third day of Teves.

11 The term chelek, used when announcing the molad on Shabbos Mevarchim, equals 1/1080 of an hour, or 3 and 1/3 seconds.

12 She’eilos of Rav Acha’ei Geon, 67; Rambam, Hilchos Shabbos 5:21; Ha’Emek She’eilah, ad loc., note 22.

13 Ha’Emek She’eilah, ibid.; Gri”z, Hilchos Kiddush HaChodesh.

14 Rambam, Hilchos Kiddush HaChodesh 7:1.

15 Because these dechiyos are extremely technical, we suffice with explaining one of them.

16 Technically, only one of the possible combinations will result in the year being this length. Of the fourteen different year prototypes, three are sheleimah leap years of 385 days.

 

What Are the Basic Rules of the Jewish Calendar?

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Thirty Days has September, April, June, November, Tishrei, Shvat, Nissan, Sivan, Av and sometimes Cheshvan[1] and Kislev. Yet a reading of Mishnah Rosh Hashanah implies that whether a month has 29 days or 30 depends on when the witnesses saw the new moon and testified in Beis Din early enough to declare the thirtieth day Rosh Chodesh. In addition, the Gemara[2] notes that Elul could be thirty days long, something that cannot happen in our calendar. How did our empirical calendar become so rigid and predictable in advance? Come with me as we explore the history and foundations of the Jewish calendar!

The Torah (Shemos 12:2) commands the main Beis Din of the Jewish people, or a Beis Din specially appointed by them, to declare Rosh Chodesh upon accepting the testimony of witnesses who observed the new moon (Rambam, Hilchos Kiddush HaChodesh 1:1, 7; 5:1). The purpose of having eyewitnesses was not to notify the Beis Din of its occurrence; the Beis Din had extensive knowledge of astronomy and already knew exactly when and where the new moon would appear and what size and shape it would have (Rambam, Hilchos Kiddush HaChodesh 2:4; Ritva on the Mishnah Rosh Hashanah 18a). The moon’s location and speed is constantly influenced by many factors, but the wise scholars of the tribe of Yissachar calculated where and when it would appear.

The Molad

As the moon orbits earth, we on earth observe it as passing through its various phases, from the very smallest crescent until full moon, and then shrinking until it disappears completely. This monthly cycle occurs because the moon has no light of its own, and only reflects sunlight back to earth. As the moon travels around the earth, the angle at which it reflects light changes. This evidences itself in the moon’s changing phases. When the moon is on the side of the earth away from the sun, we see the full moon, because it is now at an angle whereby the entire side is reflecting light to us. However, when the moon is on the side of earth nearest the sun, we see no reflection of its light at all, and that is the point of every month when the moon disappears from earthly view. The molad is the point at which the moon crosses the plane between the earth and the sun, which means it is the beginning of a new cycle, called in English the new moon and in technical jargon the point of conjunction.

From the time of the actual molad you can calculate when the moon will become visible. Chazal always kept secret how one can predict when the new moon was to appear so as to avoid false witnesses abusing the knowledge of this information (Rambam, Hilchos Kiddush HaChodesh, 11:4).

The purpose of having eyewitnesses was not to notify the Beis Din of its occurrence; rather, the Torah required the Beis Din to wait for witnesses to determine whether the 30th day (of the previous month) would be the last day of the old month or the first day of a new month. If no witnesses to the new moon testified on the 30th day, then the new month does not begin until the 31st day, regardless of the astronomic calculations (Mishnah Rosh Hashanah 24a). Thus, prior to the establishment of our current “permanent” calendar, any month could be either 29 or 30 days, dependent on when the new moon appeared and whether witnesses arrived in Beis Din to testify about this phenomenon.

By the way, we should be aware that the above description follows the opinion of the Rambam, that the preferred and original mitzvah is to declare Rosh Chodesh based on the testimony of witnesses. However, there are several early authorities, including Rav Saadyah Gaon and Rabbeinu Chananel, who hold that the primary mitzvah is to declare Rosh Chodesh on the basis of the calculations, and that use of witnesses was implemented because of certain circumstantial issues.

According to either approach, the calendar printers could not go to press until the Beis Din had declared Rosh Chodesh, which probably explains why calendar manufacture in those times was a difficult business in which to turn a profit. Perhaps this is why organizations mailed out so few fundraising calendars in the days of Chazal!

There is another commandment of the Torah – that Pesach must always occur in the Spring (Devarim 16:1). This seemingly innocuous obligation actually requires considerable manipulation of the calendar, since the months, derived from the word moon, are determined by the length of time from one new moon to the next, which is a bit more than 29 1/2 days. However, the year and its seasons are determined by the relative location of the sun to the earth, which is a bit less than 365 1/4 days. By requiring Pesach to always be in the spring, the Torah required that the calendar could not be exclusively twelve lunar months, since this would result in Pesach wandering its way through the solar year and occurring in all seasons.[3]

Among contemporary calendars, most make no attempt to accommodate the solar year and the lunar month. What we refer to as the common secular calendar, or the Gregorian calendar, is completely based on the sun. Although the year is broken into months, the use of the word “months” is borrowed from its original meaning and has been significantly changed since the months have no relationship to any cycle of the moon. Most of the secular months have 31 days, while the lunar cycle is only about 29 1/2 days, and even those secular months that have 30 days do not relate to any phase or change in the moon. Similarly, the length of February as a month of either 28 or 29 days has nothing to do with the moon. Thus, although the word month should correspond to the moon, the Western calendar is purely a solar one, with a borrowed unit “month” given a meaning that distorts its origins.

The Moslem calendar is purely a lunar calendar of twelve lunar months, some 29 days and some 30, but has no relationship to the solar year. In truth, a pure lunar calendar has no real “year,” since a year is based on the relative locations of the sun and the earth and the resultant seasons, and the Moslem year completely ignores seasons. The word “year” is used in the Moslem sense only as a basis for counting longer periods of time, but has no relationship to the sun. Thus the Moslem “year” is only 354 or 355 days long — almost 11 days shorter than a true solar year. Therefore, a Moslem who tells you that he is 65 years old is really closer to 63 according to a solar year count. He has counted 65 years that are at least ten days shorter. I trust that Guinness takes these factors into account when computing longevity, and insurance companies realize this when calculating actuarial tables.

To review: the Moslem calendar accurately tracks the moon and the months, but has no relationship to a true year, and the Western secular calendar is fairly accurate at tracking the year and its seasons, but has no relationship to the moon and its phases.

It is noteworthy that although the Moslem “year” does not correspond at all to a solar or western year, it closely corresponds to our Jewish year in a “common” year which is only twelve months long, and the Moslem month follows closely the Jewish calendar month. (We will soon explain why there is sometimes a discrepancy of a day or two.) Thus, for three years recently, Ramadan, the Moslem holy month, corresponded to our month of Elul, although this year Ramadan falls in Av. It is accurate to say that the Moslem year “wanders” its way through the seasons as it takes 33 years until a specific month returns to the same corresponding time in the solar year, and in the interim the month has visited each of the other seasons for several consecutive years. Thus, Ramadan will not coincide with Elul again this generation, but falls in Av for three years, with Tamuz for two years, and then with Sivan, etc.

However, when Hashem commanded us to create a calendar, He insisted that we use the moon to define the months, and yet also keep our months in sync with the seasons, which are dependent on the sun; to determine the dates of the Yomim Tovim. The only way to do this is to use the Jewish calendar method of occasionally adding months – thereby creating 13 month years, which we call “leap years,” to offset the almost 11 day difference between twelve lunar months and a solar year. The result of this calendar is that although each date does not fall exactly on the same “solar date” every year, it falls within a fairly close range relative to the solar year.

Who determined which year has thirteen months?

The original system was that the main Beis Din (also known as the Sanhedrin) appointed a smaller special Beis Din to determine whether the year should have an extra month added. This special Beis Din took into consideration:

1) Astronomical data, such as: When Pesach will fall out relative to the vernal equinox (the Spring day on which day and night are closest to being equal in length).

2) Agricultural data, such as: How ripe is the barley? How large are the newborn lambs and pigeons?

3) Weather: Is the rainy season drawing to a close? Is it a famine year?

4) Convenience – or more specifically, the halachic inconvenience of creating a leap year: Shemittah was never made into a leap year, and the year before shemittah usually was.

5) Infrastructure, such as: In what condition were the highways and bridges.

All of these points influenced whether the thirteenth month, the extra Adar, would be added.[4] When this system was in place, which was from the time of Moshe and Yehoshua until almost three hundred years after the destruction of the Beis Hamikdash, the main Beis Din sent written messages notifying outlying communities of the decision to create a leap year and the reasons for their decision.[5]

By the way, after the destruction of the Beis HaMikdash, the main Beis Din was not located in Yerushalayim, but wherever the Nasi of the Jewish people resided, as long as it was in Eretz Yisrael. This included several other communities at various times of Jewish history, including Teverya, Yavneh, and Shafraam.[6] Indeed, during this period sometimes the special Beis Din met outside the land of Israel — should the head of the Beis Din be in the Diaspora and there be no one of his stature remaining in Eretz Yisrael.[7]

This explains how the calendar is intended to be calculated.  Why and how our current calendar came to be will be discussed in a future article.


[1] Although the correct name of the month is Marcheshvan, we will follow the colloquial use of calling it Cheshvan.

[2] Rosh Hashanah 19b, 20a

[3] Rambam, Hilchos Kiddush HaChodesh 4:1

[4] Sanhedrin 11a- 12a

[5] Sanhedrin 11b; Rambam, Hilchos Kiddush HaChodesh 4:17

[6] Rosh Hashanah 31b

[7] Berachos 63a; Rambam, Hilchos Kiddush HaChodesh 1:8

Asarah BeTeiveis on Friday?!

In the Yeshiva where I teach, one of my students came to me rather incredulously- "I heard that the Tenth of Teiveis falls on a Friday this year—but I thought that we cannot have fast days on a Friday? I don’t remember a fast ever falling on Friday!"

Although Moshe’s halachic assumption is inaccurate, it is easy to comprehend why he made this mistake. In our current fixed calendar, the only fast day that ever falls on a Friday is Asarah BeTeiveis. And the last time this happened was exactly ten years ago, before he was old enough to fast.

There is another, more sophisticated, basis for Moshe’s question. In a "regular" (kesidrah) year Marcheshvan (usually, but inaccurately called simply "Marcheshvan") contains 29 days and Kislev 30. In such a year, Asarah BeTeiveis always falls on the same day of the week as Rosh Hashanah. And, since Rosh Hashanah cannot fall on a Friday, one might think that Asarah BeTeiveis should not fall on Friday either.

However, our fixed calendar system has fourteen "types of years," seven leap years, and seven common years. Of those fourteen "types of years," four of them result in Asarah BeTeiveis falling on Friday, two of them in a leap year and two in a common year. This is because if Rosh Hashanah falls on Thursday and the year must have a day added (sheleimah), (I explain this concept in a different article which I will be sending in one of the nearcoming weeks) the day added is the 30th of MarMarcheshvan, which postpones Asarah BeTeiveis to a day later in the week – to Friday. In addition, if Rosh Hashanah falls on Shabbos and the year must have a day deleted (chaseirah), the day subtracted is the 30th of Kislev, which moves Asarah BeTeiveis forward one day in the week – again to Friday. Since both of these scenarios can happen in either a normal year or in a leap year, there are four different "years" that result in Asarah BeTeiveis falling on Friday.

This year provides an example. Rosh Hashanah fell on Thursday and the year is sheleimah, meaning that both Marcheshvan and Kislev have 30 days, which avoids Rosh Hashanah from falling next year on Wednesday. But adding the 30th day to Marcheshvan causes Asarah BeTeiveis to fall on Friday. This type of year is referred to as a השג year, theה  standing for Thursday (the fifth day of the week), the day of Rosh Hashanah; the  ש for sheleimah, and the  ג for the day of week that Pesach will fall this year, which is Tuesday, the third day of the week, which result because this is a leap year.

(By the way, the year 5774, which occurs in three years, is also a השג year exactly as this year is, so remember not to throw away your Hebrew calendar at the end of the year; you can reuse it in three years. On the other hand, the molad times will be different, as will the times for zman keriyas shma [which is dependent on the solar calendar], so maybe that is not such a good idea. Good thing for the calendar makers.)

If we plan a bit ahead, we will discover that all four types of years when Asarah BeTeiveis falls on Friday will occur within the next few years. The year 5781 (the end of the secular year 2020), is a common year in which Rosh Hashanah falls on Shabbos. Both Marcheshvan and Kislev are 29 days that year, which results that the last day of Chanukah that year is a Friday, the 3rd of Teiveis, and the fast of Asarah BeTeiveis falls on the following Friday.

BACK TO BACK FASTS

If we look ahead to the Hebrew calendar years 5784 and 5785, corresponding roughly to the secular years 2023 through 2025, we discover the fairly unusual situation of having back-to-back years with Asarah BeTeiveis falling on Friday both in 5784 (2023) and in 5785, (when it falls on January 10, 2025), each for a different reason: In 5784, which is a leap year, Rosh Hashanah falls on Shabbos and it is a chaseirah since both Marcheshvan and Kislev have 29 days, thus causing Asarah BeTeiveis to occur one day earlier in the week than Rosh Hashanah – Friday. 5785 is a common year when Rosh Hashanah falls on Thursday and it is a sheleimah when both Marcheshvan and Kislev have 30 days. Of course, I’m sure you noticed that there is no Asarah BeTeiveis in the secular year 2024, but it falls out twice in 2025. I will explain this phenomenon shortly.

A rocket scientist once attempted to explain to me why Asarah BeTeiveis falls occasionally consecutively on Friday. I am going to attempt to explain what he told me. When Rosh Hashanah in a leap year falls on Shabbos, that year cannot be a regular leap year of 384 days, because that would cause the next Rosh Hashanah to fall on Friday, violating the rule of lo adu Rosh, since this would result in Yom Kippur falling on Sunday. To avoid this happening, that year must either be shortened by a day (chaseirah), moving the next Rosh Hashanah forward to Thursday, or by adding a day (sheleimah), pushing the next Rosh Hashanah to Shabbos. Which of these happens is dependent on when the molad of the new moon for the next Rosh Hashanah falls. But if the year is indeed chaseirah, the loss of the day moves Asarah BeTeiveis to Friday, a day earlier in the week than was Rosh Hashanah.

Now then: When the year is made chaseirah (and Rosh Hashanah of the second year falls on Thursday as a result), it sometimes results that the second year requires an extra day to avoid the following year’s molad from falling too early. What has basically transpired is that because one year was shortened by a day, the next year requires a compensation of an additional day. When this happens, both Marcheshvan and Kislev in the second year now have 30 days. This results in Asarah BeTeiveis in the second year being postponed from Thursday to Friday.

If I understood the rocket scientist correctly, the only way this phenomenon of Asarah BeTeiveis falling in two consecutive years on a Friday is when the first year is a leap year that begins on Shabbos that was chaseirah and the second year is a common sheleimah year that begins on Thursday. Every time I have found this on the calendar it has been such a phenomenon, but I take no responsibility for ascertaining that this is the only way this can happen. I make no claim to be a rocket scientist.

What did Teddy Roosevelt and Richard Nixon have uniquely in common?

The last time Asarah BeTeiveis fell in two consecutive years on Fridays was in 5733 (on December 15, 1972, when Richard Nixon was president) and 5734 (on January 4, 1974). Few of those reading this article were fasting the previous time that Asarah BeTeiveis occurred on Friday in back-to-back years since this was on December 20, 1901 and January 9, 1903. Teddy Roosevelt was president, having succeeded to the office when William McKinley succumbed on September 14, 1901, to the wounds inflicted by Leon Frank Czolgosz. According to my research, these were the only two times the phenomenon of Asarah BeTeiveis falling in two consecutive years on Fridays occurred in the Twentieth Century. Is there any significance to the fact that both Roosevelt and Nixon were Republicans? Let us wait eagerly to see who wins the election of 2020 to see who will be president in 2023 and on January 10, 2025, the next back-to-back Asarah BeTeiveis on Friday. Perhaps the Republicans can keep this streak running!

The wait for the next back-to-back Friday Asarah BeTeiveis observances after 2023 and 2025 is not quite as long. Someone planning on good health and longevity can look forward to fasting on two Fridays of Asarah BeTeiveis in the years 5831 (on December 12, 2070) and 5832 (January 1, 2072), providing an auspicious way to celebrate the secular New Year.

By now, you presumably have noted that the secular years 1902 and 1973 both missed having Asarah BeTeiveis, and that so will 2024 and 2071. That a secular year misses Asarah BeTeiveis is not particularly significant. Almost every halachic leap year causes the pushing of Asarah BeTeiveis into the next secular year, and means that Asarah BeTeiveis misses one secular year, and falls out in January and then December of the year following. As a result, seven of nineteen secular years miss out on Asarah BeTeiveis. (Actually, it is slightly less, since about twice a century Asarah BeTeiveis in a leap year falls on December 30 or 31.)

COINCIDENCE OR DELIBERATE

Biblical Source

Although it would appear that the reason no other fast occurs on a Friday is simply a coincidence of the fixed calendar, one early authority contends that observing Asarah BeTeiveis on Friday has a Tanach basis and deep halachic significance. The Avudraham explains that since the verse in Yechezkel (24:2) identifies the Tenth of Teiveis as etzem hayom hazeh, this very day, these words require that Asarah BeTeiveis be observed on the date that it occurs and may not be moved. The Avudraham expressly states that if Asarah BeTeiveis were to fall on Shabbos, we would be required to fast on Shabbos just as we are required to fast when it falls on a Friday. This means that prior to the establishing of our calendar by Hillel Hasheini, whenever Asarah BeTeiveis fell on Shabbos (during the period after the Churban), Klal Yisrael fasted on Shabbos, similar to the fasting we do when Yom Kippur falls on Shabbos! This ruling of the Avudraham seems unusual – particularly, since there is no record in the Gemara of such a halacha.

We can easily understand why the Beis Yosef (Orach Chayim 550) takes strong issue with Avudraham’s approach, and questions why one should treat Asarah BeTeiveis more strictly than any other rabbinically ordained fast. In addition, Avudraham’s position conflicts both with Rashi (Megillah 5a s.v. aval) and the Rambam (Hilchos Taanis 5:5), both of whom mention that when Asarah BeTeiveis occurs on Shabbos, the fast is postponed to Sunday.

Nevertheless, we must understand the conceptual basis why the Avudraham understands Asarah BeTeiveis to be a stricter fast than the others. It would seem that its significance is because it is the beginning of the tragedies that resulted in the churban, a message we should take to heart when we observe this fast, whether or not it occurs on Friday.

Would You Like One or Two?

On the evening of the first night of Chol HaMoed in Eretz Yisroel (corresponding to the eve of the second night of Yom Tov in chutz la’aretz), I received a curious phone call:

“Rabbi,” the female voice began, “I am calling on behalf of my friend, Rivkah.” After decades of rabbinic experience, I was convinced that this was the introduction to an embarrassing question. People often prefer pretending that they are asking for someone else — hiding behind the name of “a friend.” But this time, I was wrong.

KIDDUSH OR HAVDALAH?

“Rivkah is a student at Bnos Aliyah Seminary and is uncertain whether she should keep one day of Yom Tov or two. A few weeks ago, she visited a family for Shabbos and mentioned her predicament. The man of the house graciously told her that he answers halachic inquiries, and ruled that she need keep only one day of Yom Tov. However, upon returning to Seminary, a teacher told Rivkah that she should not ask her shaylah from just anyone, but must ask one of the seminary rabbis. Rivkah did so, and was told to keep two days. Subsequently, someone told her that she should not have asked the question a second time and must follow the first ruling she received. Now, she is in a dilemma: Should she observe the second day of Yom Tov or not?

Although most people do not have a Yom Tov issue like Rivkah did, they could still stumble into a similar predicament by making a query of two different rabbonim. As I understood the shaylah, the answer to Rivkah’s query did not involve analyzing the laws of who must observe two days, but concerned whether she must follow the first opinion or the second. Although the Gemara states that one may not ask the same shaylah twice, perhaps this applies only if someone received a strict ruling that he or she is now trying to overturn. But what happens if someone first received a lenient ruling, and then received a stricter response? In our instance, the first authority told Rivkah that she need keep only one day Yom Tov, which, according to most opinions, is considered a lenient ruling, since she now may perform melacha on the second day (Minchas Shelomoh 1:19:8). (Shu’t Chacham Tzvi #167 contends, for reasons beyond the scope of this article, that keeping one day is the stricter ruling.)

In order to resolve Rivkah’s quandary, we need to discuss the following questions:

  1. May one ask again after receiving a lenient answer?
  2. If one did, and the second authority ruled strictly, whose reply is binding? Is one still bound by the first ruling, which in Rivkah’s case was lenient, or the second, stricter ruling; or perhaps she should now ask a third authority for a final decision?
  3. Was the teacher correct in directing her to ask a second shaylah after she already received a psak?

BACKGROUND INFORMATION

Before focusing on Rivkah’s predicament, we must first understand the general principles of the topic:

The Gemara (Avodah Zarah 7a) teaches that someone who asked a shaylah and received a strict ruling may not subsequently ask the question from a different authority. I will refer to this principle as hanishal lechacham (“one who asked a Torah scholar”), based on the opening words of the Gemara’s statement.

Tosafos (Avodah Zarah 7a s.v. hanishal) inquires, “May one never question the rav’s decision? Let the different authorities debate the issue and perhaps the second will prove to the original authority that the original decision was incorrect.” Tosafos concludes that the Gemara prohibits only asking a second rav without notifying him that one has already asked the question. However, if one notifies the second authority that the question had already been asked, the second authority may oppose the decision, if he considers it mistaken. Can he actually overturn the first ruling? This depends, as there are three levels of error:

CLEAR MISTAKE

  1. If it is obvious to the second rav that the first rav erred, the second rav may inform the inquirer of the correct practice (Tosafos). This is true only if the first rav‘s ruling conflicts with accepted halachic practice or was based on inaccurate information (see Mishnah, Bechoros 28b). In these instances, the first opinion is totally disregarded, since it is erroneous. Judaism does not accept a doctrine of rabbinic infallibility; on the contrary, the Gemara records several instances where great halachic authorities erred in specific rulings (see Horiyos 2a). For example, Rabbi Tarfon ruled that a cow whose uterus was surgically removed is not kosher, as it will die shortly. The Mishnah records that when it was demonstrated that an animal can survive this surgery satisfactorily, Rabbi Tarfon acknowledged his error (Mishnah, Bechoros 28b).

PROVABLE ERROR

  1. If the second rav feels he can prove that the first one’s ruling was mistaken, but the ruling is not an obvious error, the second authority may not say anything directly to the inquirer. Instead, he should contact the first rav and share with him his proofs that the ruling was flawed. In the true style of intellectual honesty required of a Torah scholar, the first rav should carefully examine the second rav’s approach to see if it has merit. It is now up to the first rav to decide whether to change his ruling (Shu’t Panim Meiros #2; cf. Shach, Yoreh Deah 242:58; Choshen Mishpat 25:14:17). If he still feels that his first interpretation is correct, or, at least, not proven to be in error, he should maintain his original position. According to some opinions, he may retract his position if he no longer feels it to be correct, even though he cannot prove it wrong (Levush, Yoreh Deah 242:31; Aruch HaShulchan, Yoreh Deah 242:60).

A similar situation could result if the second rav knows that well-accepted authorities rule differently from the way the first rav did, and he suspects that the first rav would accept their position (see Rosh, Sanhedrin 4:6). In this situation, too, the second rav may simply notify the first rav of the variant opinion, and then it is up to the first rav to decide whether to rescind his original decision.

In all the cases we mentioned so far, the first rav’s ruling is retracted, either because it was clearly erroneous or because he himself withdrew it.

DISPUTE IN INTERPRETATION

III. If the second rav disagrees with the first rav’s conclusion, but cannot prove it incorrect, the second rav should say nothing to the questioner, who remains bound by the original decision. There is no halachic error here, but a diversity of outlook, and the first rav’s verdict cannot be overturned. Even if the first rav himself subsequently reconsiders his decision, most authorities contend that he cannot alter his own original ruling, since the original approach cannot be disproved (Shach, Yoreh Deah 242:58 and Choshen Mishpat 25:14:17; Shu’t Panim Meiros #2; Divrei Chamudos, Chullin 3:24). (However, note that the Levush, Yoreh Deah 242:31, and the Aruch HaShulchan, Yoreh Deah 242:60, rule that he can change his mind. They feel that the second rav should engage the first rav in debate, because this might change the first one’s mind.)

HOW LONG?

How long does the ruling remain binding?

The Rama (Yoreh Deah 242:31) rules that the rav’s decision is binding only for the specific instance just asked. However, if the same shaylah recurs, one may re-ask the shaylah from either the same or a different rav. The same rav himself, and certainly any other rav, may rule differently when the question recurs. Therefore, if someone asked whether one may perform a certain activity on Shabbos, was told that it is forbidden, and subsequently discovers that the consensus of poskim permits this activity, he may be lenient in the future. Similarly, a rav who ruled one way and subsequently discovered that most poskim dispute his conclusion may conclude differently the next time he is asked this question.

WHAT IF THE FIRST SCHOLAR WAS LENIENT?

So far, we have assumed that the first rav decided strictly. What happens if the first rav ruled leniently, and the questioner would like to ask someone else? This issue is germane to Rivkah asking her seminary rabbi about observing two days of Yom Tov after the first rabbi permitted her to keep only one day.

The answer to this question depends on why one may not ask a shaylah from a second authority. Here are two reasons given:

Reason #1: CONSIDERING IT PROHIBITED

Most Rishonim contend that when submitting a question to a rav, the inquirer accepts the rav’s decision as binding and must then consider the item either permitted or prohibited (Raavad quoted by Ran; Rosh). This concept is called shavya anafshei chaticha de’issura (considering something as prohibited). I will clarify this principle with a case that I discussed in a different article.

A man believes himself to be a kohen, even though there is insufficient evidence for his assumption. Since most Jews are yisroelim and not kohanim, his halachic status is a yisroel, and he has none of the rights of a kohen — he may not duchen, redeem a bechor or receive the first aliyah to the Torah. However, since he considers himself a kohen, he must assume the stringencies that result from that esteemed status: he may not come in contact with corpses, nor marry a woman forbidden to a kohen. Since he believes that he is a kohen, he is shavya anafshei chaticha de’issura, he must consider himself prohibited to do these things, as if he is a kohen.

The Rishonim mentioned above maintain that asking a shaylah means accepting the rav’s opinion as binding halacha; if he rules stringently, I must accept his verdict, and therefore I may not re-ask the question. (The exceptions mentioned previously, where the ruling can be retracted, are because the decision is considered an error and, therefore, not a valid decision.)

This approach rules that the principle of hanishal lechacham applies only when the first rav ruled stringently. If he ruled leniently, I am permitted to follow his ruling, but not obligated to, and therefore, I may re-ask the shaylah from a different rav (see Tosafos, Avodah Zarah 7a s.v. hanishal). Thus, Rivkah may ask her shaylah from the seminary rabbi, notwithstanding the first ruling she received. We will soon discuss whether she is obligated to keep the second day of Yom Tov, once she received this second ruling.

Reason #2: RESPECT FOR A TALMID CHACHAM

Other authorities explain that re-asking a shaylah from a second rav affronts the respect due the first rav, by implying that one is questioning his competence (cited by Ran to Avodah Zarah. See there that he also quotes an additional reason.) This rationale forbids re-asking a question, even if the first rav ruled leniently, as it is still offensive to the rav’s honor. Following this approach, Rivkah should not have asked the seminary rabbi, once she had already asked someone qualified to answer her shaylah.

In view of the second reason, Rivkah’s teacher should certainly have asked her own shaylah as to whether to instruct Rivkah to ask her shaylah again.

Do any other differences result from the dispute as to why one may not re-ask a shaylah? Indeed, they do.

A BRACHA DISPUTE

Many halachic issues are not matters of being strict versus lenient, but simply questions regarding correct procedure. For example, whether or not to recite a bracha in a certain instance, which bracha to recite, or whether to repeat a tefillah are all instances where there is no “stricter” or “more lenient” side of the question. Both sides of the question involve a stringency, and therefore, the principle of shavya anafshei chaticha de’issura is not applicable.

Those who ban re-asking a question because of shavya anafshei chaticha de’issura should therefore permit re-asking any question of this type, in order to receive a more accurate or authoritative response. On the other hand, those who ban re-asking a question because it is offensive to a scholar’s honor should prohibit it in this instance, too, since it implies a lack of competence on the part of the first rav asked.

Before resolving Rivkah’s dilemma, we need to explore one other fascinating point:

A DISPUTE BETWEEN THE TALMUDS?

When the Gemara Bavli (Avodah Zarah 7a) cites the prohibition of remaking a halachic inquiry, it refers only to cases where the first rav answered stringently, but mentions no cases where the first rav ruled leniently. This implies that the Bavli explains the reason for this prohibition like the first approach – that one has accepted the prohibition of the rav.

However, the Yerushalmi (Shabbos 19:1) quotes the following anecdote:

Rabbi Simon permitted something which Rabbi Ami subsequently prohibited. Rabbi Simon was upset; is it not said that if one sage permitted something, a second sage may not prohibit it?

This Yerushalmi appears to rule that one may not re-ask a question, even if one received a lenient ruling, which is impossible according to the first approach. Thus, the Yerushalmi appears to understand that the reason one may not re-ask a question is the talmid chacham’s honor, the second approach cited. This would imply that the two Talmuds dispute the exact question upon which our dear Rivkah and her teacher stumbled!

The Rishonim prefer to avoid saying that the two Talmuds disagree, suggesting different approaches to resolve this contradiction.

AN ALTERNATIVE READING

Tosafos (Avodah Zarah 7a s.v. hanishal) suggests reading the last statement of the Yerushalmi rhetorically, as opposed to being a support for Rabbi Simon’s position. The passage now reads:

Rabbi Simon permitted something which Rabbi Ami subsequently prohibited. Rabbi Simon was upset. The Yerushalmi now questions the validity of Rabbi Simon’s reaction:

“Does it say anywhere that if one sage permitted something, a second sage may not prohibit it?”

Following Tosafos’ approach, the Yerushalmi rules, exactly as the Bavli implies, that the prohibition to re-ask a question applies only when the first scholar decided stringently. However, when he ruled leniently, a second scholar may rule freely on the case.

On the other hand, the Rosh explains the Yerushalmi as I explained originally, that Rabbi Simon objected to Rabbi Ami’s strict ruling as halachically objectionable, after he (Rabbi Simon) had permitted the matter. The Rosh quotes this approach as definitive halacha, meaning that hanishal lechacham is prohibited because of the honor of the first rav. The Rosh appears to contend that both reasons are true, the Bavli emphasizes one reason, and the Yerushalmi the second. This approach maintains that one may, indeed, not seek out a second rav’s opinion, whether the first rav was lenient or strict.

HOW DO WE RULE?

How do we rule in this dispute?

Most halachic authorities rule that the law of hanishal lechacham applies only when the initial ruling was strict, but if it was lenient, one may, indeed, re-ask the shaylah (Shach, Yoreh Deah 242:59; Gra). However, there are some who rule, like the Rosh, that hanishal lechacham applies whether the initial ruling was strict or lenient and therefore forbid re-asking a question, even if one received a lenient ruling (Rama, Yoreh Deah 242:31). According to the first approach, there was nothing wrong with Rivkah re-asking her question.

CONCLUSION

Now that Rivkah already re-asked the question, must she keep one or two days of Yom Tov? According to those who rule that hanishal lechacham is because one has accepted the stringent opinion, once Rivkah re-asked the question she is bound to follow the second, stricter, ruling. Since most authorities rule this way, one who re-asks the question from a second authority will be obligated to follow his opinion, if he is stricter. No matter how many people one asks, one will be always obliged to follow the strictest ruling. Thus, Rivkah should celebrate two days of Yom Tov this Pesach.

The final psak Rivkah received applies only to the question she asked about Pesach. When Shavuos arrives, she may ask again whether to observe one day Yom Tov or two. May she direct her question to a particular rav, knowing what answer she wants to receive? That is a topic for a different article.