Question #1: Fasting on Friday
May we fast on a Friday?
Question #2: An Unusual Year
In what ways is this year different from most other years?
Question #3: Who Stole the Date!
Why do some years miss having Asarah Beteiveis?
Question #4: Unusual Presidents
What did Teddy Roosevelt and Richard Nixon have in common?
Introduction
In a previous year when the Tenth of Teiveis fell on Friday, Moshe, one of my students where I taught at the time, came to me, rather incredulously, “I heard that Asarah Beteiveis falls on a Friday this year—but I thought that we cannot have fast days on a Friday? I don’t remember ever fasting on Friday!”
Answer
Although Moshe’s halachic assumption is inaccurate — there is no halacha banning fast days on Fridays — it is easy to comprehend why he thought so. In our current, fixed calendar, the only fast day that ever falls on a Friday is Asarah Beteiveis, and indeed it happens this year. Asarah Beteiveis last coincided with Friday seven years ago, and the time before was three years prior, which was the year that Moshe posed his observations.At the time, ten years had transpired since Asarah Beteiveis had fallen on a Friday, certainly way before Moshe was old enough to fast.
To explain why Asarah Beteiveis is the only fast that falls on a Friday requires a bit of complicated explanation about our calendar, but it is well worth it to have a deeper understanding of this very important institution. So find a relaxing place to do some entertaining calculations.
First, we need some historical background.
When the Torah commands us to create a calendar, it includes two different responsibilities: First, that Rosh Chodesh and the length of each month are determined on the basis of when the new moon appears, and, second, to have the holiday of Pesach fall in the spring and the holiday of Sukkos in the autumn (in the northern hemisphere). Thus, we have two separate and very different requirements, one of having the months determined by the moon, which is a little more than every 29½ days, and the second of having years that coordinate with the seasons, which follow the solar year, which is a bit less than 365¼ days.
Sanhedrin calendar
To accomplish having the dates and holidays fall according to the seasons, the halacha is that some years have 12 months, or approximately 354 days, and others have 13 months, or approximately 384 days. Since 12 Hebrew months is shorter than a solar year, unless we occasionally add another month, Pesach would fall approximately 10 days earlier each year until, eventually, it would be in the winter. Adding an extra month periodically adjusts that Nissan remains in the spring.
The mitzvah of the Torah is that the Sanhedrin is responsible every month to decide whether a month is 29 or 30 days long, and of deciding whether a year should have an extra month. In the latter case, the head of the Sanhedrin appointed a special committee to review the relevant information and determine whether the year should be 13 months or only 12.
Hillel’s calendar
Initially, these decisions were made by the heads of the Sanhedrin, and, indeed, when Moshiach comes, we will again have this procedure. This was the system in place for thousands of years – from the time of Moshe Rabbeinu until almost 300 years after the destruction of the second Beis Hamikdash. At that time, the head of the Sanhedrin, Hillel Hanasi (often called Hillel II or Hillel III by historians, to avoid confusion with his better-known ancestor, Hillel Hazakein, usually simply called “Hillel”), realized that, because of Roman persecution, the Sanhedrin’s days were numbered, and it would be necessary to switch to a different method for determining the calendar. Hillel Hanasi implemented a temporary Jewish calendar, which is the one that we currently use. Although many people refer to it as a “permanent calendar,” it will be in use only until we again have a Sanhedrin, which will then be in charge of the calendar.
Hillel’s calendar kept the same, basic structure of 29- and 30-day months and 12- and 13-month years, but it is based purely on calculation and not on observation or changes of circumstance. The two major changes in this new calendar are:
A leap of fate
The leap years occur following a regular pattern of seven leap years and 12 non-leap (usually called “common”) years in a 19-year cycle. The third, sixth, eighth, eleventh, fourteenth, seventeenth and nineteenth years of the cycle are always leap years, and the rest are common years.
The new calendar bases itself on an estimate, an average time that it takes the moon to revolve around the Earth. This molad calculation is that each new moon appears 29 days, 12 hours, and 793 chalakim (singular: chelek) or 793/1080 of an hour after the previous new moon. Once one knows when the new moon, called the molad, occurred on the previous Rosh Hashanah, one could now add either 12 or 13 times the above figure 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. (The term chelek, used on Shabbos Mevorchim when announcing when the molad is, equals 1/1080 of an hour, or 3 and 1/3 seconds.)
The haves vs. the have-nots
In Hillel’s calendar, most months have a determined number of days, either 29 or 30, and only in two months, Marcheshvan and Kislev, does the number of days vary. Furthermore, whether those two months are 29 or 30 days long has nothing to do with the appearance of the new moon, which was the most critical factor under the Sanhedrin calendar, but is determined by two Rosh Hashanos (Rambam, Hilchos Kiddush Hachodesh 8:5), the Rosh Hashanah of the coming year and thatof the year following.
A year in which both Marcheshvan and Kislev have only 29 days is called chaseirah, lacking or defective; one in which Marcheshvan has 29 days and Kislev has 30 is called kesidrah, as expected or regular; and one in which both Marcheshvan and Kislev have 30 days is called sheleimah, full or excessive.
The terms chaseirah, kesidrah, and sheleimah apply in both common and leap years. Thus, in Hillel’s calendar, all common years are either 353 days (if both Marcheshvan and Kislev have 29 days), 354 days (if Marcheshvan has 29 days and Kislev has 30) or 355 days (if both Marcheshvan and Kislev have 30 days)
In a leap year, Adar Rishon always has 30 days, and Adar Sheini always has 29 days. Thus, the addition of an extra month of Adar in a leap year always adds exactly thirty days, and leap years are either 383 days (if both Marcheshvan and Kislev have 29 days), 384 days (if Marcheshvan has 29 days and Kislev has 30) or 385 days (if both Marcheshvan and Kislev have 30 days)..
Another major innovation
Did you ever notice that Yom Kippur never falls on Friday or Sunday? If it did, we would observe two consecutive days that both have the stringency of Shabbos. Indeed, when the calendar was based on observation, this could and did happen (She’iltos of Rav Acha’ei Geon, #67; Ha’emek She’eilah ibid, Note 22; Rambam, Hilchos Shabbos 5:21). However, Hillel’scalendar does not allow Yom Kippur to fall on either a Sunday or a Friday, and 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, it was halachically more important to have Rosh Chodesh fall on its correct day than to be concerned about the difficulties created when these holidays fall on or next to Shabbos (Ha’emek She’ailah ibid; Gri”z, Hilchos Kiddush Hachodesh). Once we fulfill the mitzvah in a less-preferred way with Hillel’s “permanent” calendar, keeping Yom Kippur from falling on Friday or Sunday and keeping Hoshana Rabbah from falling on Shabbos are factors to be included in establishing the calendar.
To accommodate these innovations, Rosh Hashanah must fall only on Monday, Tuesday, Thursday or Shabbos. Were it to fall on Sunday, Hoshana Rabbah would be on Shabbos; on Wednesday, Yom Kippur would be on Friday; and on Friday, Yom Kippur would be on Sunday. When Rosh Hashanah in the coming year would naturally fall on Sunday, Wednesday or Friday, an extra day is added to the calendar to move Rosh Hashanah to Monday, Thursday or Shabbos (Rambam, Hilchos Kiddush Hachodesh 7:1). This is the predominant reason why Marcheshvan and Kislev are sometimes 29 days and sometimes 30 — to make the exact length of the years flexible.
There is one other factor: Sometimes, Rosh Hashanah takes place not on the day of the molad, but the next day, because the molad occurs on the afternoon of Rosh Hashanah and is not visible 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 for interrogating potential witnesses testifying to the appearance of the new moon. Hillel’s calendar also does not allow Rosh Hashanah to be established on a day when the molad falls on its afternoon.
In order to accomodate all these various calendar requirements, Hillel Hanasi established four rules, called dechiyos, which, together with the astronomicalcalculation used and the 19-year leap year rotation, form the basis for determining our calendar. (Because these dechiyos are extremely technical, I will not explain them.)
Because the nineteen-year cycle synchronizes the lunar calendar with the solar year, the Hebrew and English dates of births, anniversaries and other occasions often coincide on the nineteenth anniversary of the event. If yours does not, but is off by a day or two, do not fret. Your record-keeping is accurate, but the cycle of nineteen years only relates to whether it is a leap year, not to whether the years are of the exact same length. As explained above, the lengths of Marcheshvan and Kislev are determined by other factors, and the secular year also varies in length, with the occasional addition of the 29th of February, which influences this also. These factors affect whether your 19th, 38th or 57th birthday or anniversary coincides exactly with its Hebrew/secular counterpart, or whether it varies slightly.
Fourteen types of years
Based on all these calculations, there are seven prototype years for a common year and seven for a leap year that fulfill the calendar rules. Each of these fourteen template “years” is called by a three-letter acronym, called a kevias hashanah, 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.
Let’s use this year as our example: Rosh Hashanah fell on Thursday. Both Marcheshvan and Kislev are 30 days this year; therefore, this year’s kevias hashana is השא, meaning that Rosh Hashanah fell on the fifth day of the week (ה), the year is sheleimah (ש), and the first day of Pesach is on Sunday, the first day of the week (א).
No letter is used to denote whether the year is a common or leap year, because this is understood by knowing how many days of the week Pesach follows Rosh Hashanah. In a common year that is kesidrah, Pesach falls two days later in the week than Rosh Hashanah, and in a leap year, it falls four days later, the two additional days being the extra two days that the extra month of Adar Rishon, thirty days long, adds to the day of the week count. Of course, these calculations must be adjusted one day in either direction, if the year is chaseirah or sheleimah. Either way, the number of days between Rosh Hashanah and Pesach (and whether it is chaseirah or sheleimah) tells us whether it is a common or leap year, so there is no need to include this in the acronym.
Back-to-back
During the Hebrew calendar years 5784 and 5785, 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 was a leap year, Rosh Hashanah fell on Shabbos and the year was a chaseirah — both Marcheshvan and Kislev had 29 days. 5785 is a common year in which Rosh Hashanah fell on Thursday and it is a sheleimah, because both Marcheshvan and Kislev have 30 days. When this happens Asarah Beteiveis of the second year falls exactly 385 days after the previous Asarah Beteiveis. Since the number 385 is perfectable divisible by seven, the number of the days of the week, the dates will fall on the same weekday.
At this point, we can explain another of our opening questions: What did Teddy Roosevelt and Richard Nixon have in common?
The last time Asarah Beteiveis fell on Friday in two consecutive years was in 5733 (on December 15, 1972, when Richard Nixon was president) and 5734 (on January 4, 1974). No one reading this article was 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. Both of these fasts occurred when Teddy Roosevelt was president, having succeeded to the office on September 14, 1901, when William McKinley succumbed to his wounds inflicted by Leon Frank Czolgosz. Thus, Teddy Roosevelt and Richard Nixon were the only two people in the twentieth century to have Asarah Beteiveis fall on Friday in two consecutive years while they were President of the United States!
The next wait for back-to-back Friday Asarah Beteiveis observances after 5784 and 5785 is not quite as long. Someone blessed with 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).
You presumably have noted that the secular, or solar, years 1902, 1973, 2024 and 2071 all miss having Asarah Beteiveis. This is, in itself, not particularly significant. Almost every halachic leap year causes the pushing of Asarah Beteiveis into the next secular year. 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 after a leap year falls on December 30 or 31.)
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 this on the basis of the following pesukim in the book of Yechezkel: “And the Word of Hashem came to me in the ninth year in the tenth month (Teiveis) on the tenth of the month, saying, ‘Son of man, write the name of this date, this very day (etzem hayom hazeh); the king of Bavel has surrounded Yerushalayim, on this very day, be’etzem hayom hazeh’”(Yechezkel 24:1-2). Since Yechezkel identifies the Tenth of Teiveis as etzem hayom hazeh, this very day, and then even repeats this assertion, 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, in his opinion, 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.
The Beis Yosef (Orach Chayim 550) takes strong issue with Avudraham’s approach, and questions why Asarah Beteiveis should be treated differently from any other rabbinically ordained fast. In addition, Avudraham’s position conflicts 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 on which the Avudraham, himself a well-respected Spanish rishon, 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.
Conclusion
The pasuk promises us that the “Fast of the Fourth (month, the Seventeenth of Tammuz, the fourth month counting from Nissan), the Fast of the Fifth (Tisha Be’av), the Fast of the Seventh (Tzom Gedalyah) and the Fast of the Tenth (Asarah Beteiveis) shall be for celebration and happiness for the household of Yehudah” (Zecharyah 8:19). May we use the fast days and other days of mourning for reflection and teshuvah, so that the words of the prophet are fulfilled speedily and in our days!
