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?

clip_image002

 

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.

Do I One or Two? — What Determines Whether One Observes a Second Day of Yom Tov?

Question #1: Zev is studying in Yeshiva in Eretz Yisroel and has decided that he wants to settle there, although his parents, who support him, live in Flatbush. How many days of Yom Tov should he observe?

Question #2: Avi and Rutie, who are native Israelis, have accepted teaching positions in chutz la’aretz for two years, but certainly intend to return to Eretz Yisroel afterwards. Must they observe both days of Yom Tov while they are in chutz la’aretz?

Question #3: Meira, studying in seminary in Israel, is baffled. “Some of my friends who have decided to stay in Eretz Yisroel were told to keep two days Yom Tov, others were told to keep one, and still others were told not to do melacha on the second day, but otherwise to treat is as a weekday. I have been unable to figure out any pattern to the answers they receive. Can you possibly clarify this for me?”

Indeed, Meira’s confusion is not unusual since poskim differ greatly concerning what guidelines determine whether one observes one day of Yom Tov or two. Before analyzing this dispute, we need some background information on how the calendar was established in the era of the Sanhedrin:

THE HALACHIC MONTH

All months in the Jewish calendar are either 29 or 30 days long, reflecting the amount of time that it takes for the moon to revolve around the earth, which is somewhat more than 29½ days. Therefore, Rosh Chodesh, the first day of the new month, is always either the 30th or the 31st day following the previous Rosh Chodesh.

What determines whether a month is 29 days or 30?

The Torah 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, which had extensive knowledge of astronomy, already knew exactly when and where the new moon would appear and what size and shape it would be (Rambam, Hilchos Kiddush HaChodesh 2:4; Ritva on the Mishnah Rosh Hashanah 18a). Rather, the Torah required the Beis Din to wait for witnesses in order to declare the 30th day as Rosh Chodesh. If no witnesses to the new moon arrived on the 30th day, then the 31st day becomes Rosh Chodesh, regardless of the astronomic calculations (Mishnah Rosh Hashanah 24a).

DETERMINING YOM TOV

The date of all Yomim Tovim is determined by Rosh Chodesh, or, more specifically, by either Rosh Chodesh Tishrei or Rosh Chodesh Nissan (Mishnah Rosh Hashanah 21b). (Shavuos, which occurs on the fiftieth day after Pesach, is therefore also dependent on Rosh Chodesh Nisan [Yerushalmi, Rosh Hashanah 1:4].) Therefore in earlier days, even someone fully versed with all the astronomical information would be unable to predict which day was actually Rosh Chodesh, since Rosh Chodesh was not based exclusively on calculation, but on observation and the decision of the Beis Din (Rambam, Hilchos Kiddush HaChodesh 5:1-2). Since the calendar printers could not go to press until the Beis Din had declared Rosh Chodesh, calendar manufacture in those times would have been a difficult business in which to turn a profit. Perhaps this is why people mailed out so few fundraising calendars in the days of Chazal!

KEEP INFORMED

A major concern of Chazal was how to alert the Jewish communities, both inside and outside Eretz Yisroel, when to observe Rosh Chodesh and Yom Tov. How indeed did the Beis Din do this?

THE MOUNTAINTOP ALERT

No, this is not the name of a rural West Virginia newspaper. Rather, this refers to the system Beis Din used to disseminate the day they had declared Rosh Chodesh. A representative of Beis Din would climb a mountain peak on the night after the declaration of Rosh Chodesh and wave a long torch in a prearranged pattern. When a second agent posted on a far off summit saw the light of the burning torch, he in turn waved a long torch from his peak. This heralded the news to a crest on his horizon, where a third agent began waving his torch. Although this ancient system was less effective than telephone or e-mail, it worked so efficiently that Jewish communities as distant as Bavel knew that very night that the 30th day had been declared Rosh Chodesh, and were able to observe the Yomim Tovim on the correct day (Mishnah Rosh Hashanah 22b; Ritva on the Mishnah 18a).

A TORCH-LESS NIGHT

The torch system was used only if Rosh Chodesh was declared on day 30. If no witnesses arrived in Beis Din on the 30th, making Rosh Chodesh on the 31st day, no mountaintop torches were ignited. Thus, the distant communities knew: Torches the night after the 30th meant that the previous day had been Rosh Chodesh; no torch that night meant that the next day was Rosh Chodesh. To paraphrase Paul Revere: “One if by day, none if tomorrow.”

This signalling system functioned excellently until the Cusim, an anti-Semitic people who settled in Eretz Yisroel, disrupted it by deliberately kindling torches on the night after the 30th day even when Beis Din had not declared the previous day Rosh Chodesh. The Cusim’s goal was to cause Jews to observe Yom Tov a day early and thereby desecrate the true Yom Tov (Mishnah Rosh Hashanah 22b). Now the Beis Din needed to resort to a different approach, appointing human runners to notify people of the proper day of Yom Tov. Obviously, these runners could not cover vast distances as quickly as the previous torch system, and it took considerably longer to notify people of the day of Rosh Chodesh – what previously took hours, now took weeks.

Although the human express successfully informed Jewish communities as distant as Syria of the correct dates of the upcoming Yomim Tovim, the runners did not always reach the more distant Babylonian communities in time for Yom Tov (Mishnah Rosh Hashanah 18a). These communities were now unsure whether the Roshei Chadashim of Nissan and Tishrei had been on the 30th day or the 31st, and were therefore uncertain which day was Yom Tov. Out of doubt, they observed Yom Tov on both days — this was the origin of observing two days of Yom Tov in the Diaspora, Yom Tov Sheini shel Galuyos (Rambam, Hilchos Kiddush HaChodesh 3:11).

(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. This included several other communities at various times of Jewish history, including Teverya, Yavneh, and Shafraam [Rosh Hashanah 31b].)

WHICH COMMUNITIES KEPT TWO DAYS?

Whether a town observed one or two days of Yom Tov depended on whether the runners could arrive there in time. Since the runners did not travel on Shabbos or Yom Tov, any place further than ten travel days from the main Beis Din was forced to observe two days of Sukkos. On the other hand, the runners announcing Rosh Chodesh Nissan had two extra travel days before the onset of Pesach.

OBSERVING TWO DAYS OF SUKKOS AND ONE OF PESACH?

Theoretically, one could have numerous different communal practices depending on the community’s distance from the main Beis Din. For example, a town located more than ten days journey from the Beis Din but less than twelve, would be informed of the correct day of Rosh Chodesh before Pesach, but not before Sukkos. Theoretically, this town would observe two days of Sukkos and one day of Pesach. Even more commonly, many communities would observe two days at the beginning of Yom Tov, but only one at the end, after being notified of the correct date of Rosh Chodesh.

However, since Chazal did not want a variety of different practices, they instituted that any place that could not reliably expect the messengers before Sukkos should observe two days Yom Tov on all Yomim Tovim even for those when they certainly knew which was the correct day of Yom Tov (Rosh Hashanah 21a). Thus, although everyone knew which day to observe Shavuos, as it always falls fifty days after Pesach, every community that kept two days of Sukkos was required to observe two days of Shavuos. (Because of the danger involved in people fasting for two consecutive days, Chazal ruled that people needed to observe only one day of Yom Kippur and could assume that Elul was only 29 days long [see Rosh Hashanah 21a].)

INCREASED PERSECUTION

During the later times of the Gemara, Roman persecution made it impossible to continue declaring Rosh Chodesh based on testimony, and Hillel II instituted a calendar based purely on calculation without observation (Rambam, Hilchos Kiddush HaChodesh 5:2-3). Now a knowledgeable Diaspora Jew could make the same calculation as the Jews in Israel and the original rationale for observing two days of Yom Tov no longer existed. Nevertheless, Chazal required the Diaspora communities to continue observing two days of Yom Tov.

WHY KEEP TWO DAYS?

Why did Chazal require these communities to observe two days of Yom Tov if the original reason for this practice had ceased to exist?

Chazal were concerned that at some time in the future, persecution might render it impossible for Jews to be aware which day was Yom Tov (Beitzah 4b). Observing two days of Yom Tov reduces the possibility that they might violate Yom Tov or eat chometz on Pesach as a result of an error in calculation. Although this concern also existed in Eretz Yisroel, Chazal did not require the communities there to observe two days Yom Tov since the practice was never instituted there. However, since the Diaspora communities were already observing two days of Yom Tov, Chazal continued this practice, albeit for a new reason. As a result, the Jewish communities of Israel observe one day of Yom Tov and those of the Diaspora observe two.

WHO KEEPS TWO DAYS OF YOM TOV?

Although whether a community observed one day of Yom Tov or two should depend on whether it was within ten travel days of the main Beis Din, certain villages near the Beis Din were off the messengers’ route and consequently did not find out in time. As a result, these communities observed two days of Yom Tov even though they were within Eretz Yisroel (Rambam, Hilchos Kiddush HaChodesh 5:9). Some Rishonim contend that even today many communities in Eretz Yisroel must observe two days of Yom Tov (Rambam, Hilchos Kiddush HaChodesh 5:9). The accepted practice is that all Eretz Yisroel observes only one day of Yom Tov since that was the practice of most places in Eretz Yisroel when the calendar was dependent on observation (Ritva, Rosh Hashanah 18a; Minchas Shelomoh 2:44).

Thus far, we have discussed the rules governing whether a community observes two days of Yom Tov or not. However, all the questions mentioned at the beginning of this article deal with how many days of Yom Tov an individual must observe.

A FISH OUT OF WATER — VISITING CHUTZ LA’ARETZ

What is the halacha if an Eretz Yisroel resident finds himself in chutz la’aretz for Yom Tov? Must he observe two days of Yom Tov because of local custom, or may he follow his hometown practice of observing one day?

The Shulchan Aruch (496:3) rules as follows: “People who live in Eretz Yisroel who are in chutz la’aretz are forbidden to perform melacha (forbidden work) on the second day of Yom Tov even if they intend to return to Eretz Yisroel.”

No one should know that they are not observing Yom Tov, and for this reason, they must wear Yom Tov clothes (Shu”t Radbaz #1145; Magen Avraham). According to most opinions, they may not perform work even in private (Shu”t Radbaz #1145; Magen Avraham; Chayei Odom 103:3; Gra”z; Mishnah Berurah; Aruch HaShulchan, all based on Tosafos to Pesachim 52a s.v. BiYishuv. However, Shu”t Mabit 3:149 and Taz [496:2] are lenient.)

However, since it is technically not Yom Tov for them, they pray according to the practice of Eretz Yisroel on this day, even donning tefillin, although they must do so in private (Shu”t Radbaz #1145; Shu”t Avkas Rocheil #26).

A CHUTZNIK IN THE KING’S PALACE — VISITING ERETZ YISROEL

Does a chutz la’aretz resident visiting Eretz Yisroel observe one day Yom Tov or two?

According to most opinions, a chutz la’aretz resident visiting Eretz Yisroel must continue to observe two days Yom Tov until he or she assumes residence in Eretz Yisroel (Shu”t Avkas Rocheil #26; Shaarei Teshuvah 496:2; She’eilas Yaavetz #168; Birkei Yosef 496:7).

One prominent posek contends that a chutz la’aretz resident visiting Eretz Yisroel does not observe the second day of Yom Tov. His reasoning is that observing two days of Yom Tov is a carryover from when people in chutz la’aretz were unable to determine which day was definitely Yom Tov. In that era, if someone from chutz la’aretz visited Eretz Yisroel, why would he observe two days of Yom Tov if he knew that the second day was not Yom Tov (Shu”t Chacham Tzvi #167)? (The Chacham Zvi himself forbids observing the second day of Yom Tov in Eretz Yisroel because of concerns about bal tosif, adding to the mitzvah, a topic we will leave for a different time.)

Although the Chacham Tzvi’s argument seems logical, almost all other halachic authorities reject his conclusion. It should be noted that even the Chacham Zvi’s son, Rav Yaakov Emden followed the majority opinion unlike his father (She’eilas Yaavetz #168. However, note that the Gra”z 496:11 cites the Chacham Tzvi’s approach as the primary opinion.)

May people from chutz la’aretz organize a second-day Yom Tov minyan? This is an old dispute that continues to this day. Although many poskim object to the practice, contending that one should not act publicly differently from local practice, the custom to have second-day Yom Tov minyanim in Eretz Yisroel is mentioned favorably by Rav Yosef Karo, the author of the Shulchan Aruch, as a well-established practice (Shu”t Avkas Rocheil #26). In most communities today it is the norm for chutz la’aretz visitors to conduct second day Yom Tov minyanim, and even to advertise them.

A TEMPORARY RESIDENT

At the beginning of this article I mentioned several common situations where it is not obvious whether one should comport himself as a resident of Eretz Yisroel or of chutz la’aretz. What determines whether one should observe two days of Yom Tov? Whether one observes two days of Yom Tov depends on whether one is considered a Diaspora resident or not, concerning which we find a wide range of halachic opinion. Here is a sampling of the opinions:

ONE YEAR

Some contend that one who plans to stay for a year should consider himself a resident of his new domicile even if he intends to return eventually (Aruch HaShulchan 496:5; Shu”t Avnei Nezer, OC 424:27). These authorities compare this law to the following Mishnah (Bava Basra 7b):

“You can force someone to contribute to the construction of the walls and reinforcements of a city… How long must he be in the city to consider him a resident? Twelve months. And if he purchased a residence he is considered a resident immediately.” The Gemara (Bava Basra 8a) compares this law to similar responsibilities for tzedakah and some other mitzvos.

According to this approach, Avi and Rutie, who will be teaching in chutz la’aretz for two years, certainly follow all the practices of chutz la’aretz for Yom Tov (see also Shu”t Yechaveh Daas 3:35).

LONG TERM INTENT

On the other hand, a different early authority ruled that time is not the factor in deciding whether one is considered a resident of Eretz Yisroel or of chutz la’aretz, but one’s long term intent. If one’s plans are to return to Eretz Yisroel, one should daven according to Eretz Yisroel practice, even if one is in chutz la’aretz for several years. Someone in Eretz Yisroel who intends to return to chutz la’aretz should observe two days Yom Tov. However, this halachic authority included one main exception to his rule: If one travels with one’s family and establishes a livelihood in his new locale, he should consider himself a resident of where he is now, since people tend to remain in a place where their livelihood is secure (Pri Chodosh, Orach Chayim 468 s.v. vira’isi).

However, many authorities judge contemporary circumstances differently from those of earlier generations. Since today people travel and even relocate relatively easily, the fact that one’s family and livelihood is currently in one location does not automatically make one a permanent resident of that place for the purposes of determining whether one observes one day of Yom Tov or two. Because of this consideration, Rav Moshe Feinstein ruled that someone studying in kollel in Eretz Yisroel should keep two days Yom Tov unless both he and his wife have decided to remain in Eretz Yisroel (Shu”t Igros Moshe, OC 3:74). Rav Moshe has several other published teshuvos on the subject, each person’s case being someone different, and in each case Rav Moshe determines whether the person should be considered a resident of Eretz Yisroel or one of chutz la’aretz.

ALWAYS YOM TOV IN ERETZ YISROEL

Rav Shlomoh Zalman Auerbach (Minchas Shelomoh 1:19:7) issued the following ruling: He contends that someone who owns a residence in Eretz Yisroel that he uses for every Yom Tov need keep only one day of Yom Tov while in Eretz Yisroel, even though he lives in chutz la’aretz the rest of the year. Rav Shlomoh Zalman’s logic is that this individual no longer has the custom of keeping two days of Yom Tov since he is always in Eretz Yisroel for Yom Tov.

A YESHIVA BACHUR WHO INTENDS TO REMAIN IN ERETZ YISROEL

What is the halachic status of a yeshiva bachur studying in Eretz Yisroel whose family lives in chutz la’aretz, but who intends to remain in Eretz Yisroel long-term? Can he establish a different custom from his family?

In answering a different question, the Magen Avraham (468:12) contends that a yeshiva bachur who is in one place for two or three years does not take on the customs of his yeshiva town. On the other hand, other sources quote that accepted practice is that a yeshiva bachur from chutz la’aretz attending a yeshiva in Eretz Yisroel observes only one day of Yom Tov (Shaarei Teshuvah 496:2). Are these two sources in dispute? Rav Moshe Feinstein contends that they are not, explaining that a student who is financially dependent on parents who have not accepted his decision to remain in Eretz Yisroel should follow their practice, whereas if he is financially on his own, or they agree to support him in Eretz Yisroel, he observes only one day of Yom Tov (Shu”t Igros Moshe, OC 2:101).

Others disagree, contending that if he might remain in Eretz Yisroel, he need observe only one day of Yom Tov. According to this approach, the Magen Avraham considered him a resident of his parents’ town only if he is certain that he is returning there after his Yeshiva years (Shu”t Yabia Omer 6:oc:40; Shu”t Yechaveh Daas 1:26).

“A DAY AND A HALF”

A colloquial expression has developed referring to someone as observing Yom Tov for “a day and a half.” This term does not mean that the person observes Yom Tov for 36 hours. It means that the rav who paskined felt uncertain whether he/she should be observing one day Yom Tov or two, and therefore ruled that he/she should not perform any melacha on the second day of Yom Tov, but should daven and observe it otherwise as a weekday.

We can now begin to comprehend Meira’s question:

“Some of my friends have been told to keep two days of Yom Tov, others were told to keep one, and still others were told not to work on the second day but otherwise to treat is as a weekday. I have been unable to figure out any pattern to the answers they receive.”

Truthfully, there is a very wide range of opinion what determines whether one observes one day of Yom Tov or two. Thus, Meira’s confusion is very understandable. Each friend’s rabbi may be applying completely different criteria to determine how many days of Yom Tov to observe, and that is why Meira cannot figure out any pattern. Obviously, someone should ask his or her rav what to do and follow his instructions.

The Torah refers to the Yomim Tovim as Moed. Just as the Ohel Moed is a meeting place between Hashem and the Jewish people, so too a moed is a meeting time for Hashem and His people (Hirsch, Vayikra 23:3 and Horeb). Perhaps being more distant from Hashem in chutz la’aretz necessitates an extra day to celebrate our unique relationship with Him!