Genealogists concern themselves with names, dates, and places, but they can be located and understood only in terms of the context in which they existed. Accurate dates are indispensible for many reasons—the scheduling of religious observances and the discovery of valuable documents to name just two. Sometimes, however, dates are more complicated than is obvious at first. When dealing with dates that involve Yiddish-speaking ancestors especially, Jewish genealogists must deal with at least three calendars, the Luach (Hebrew calendar) and two civil calendars—Julian and Gregorian. Date discrepancies often occur as a result and may be obscured (or even created) by the automatic conversion of dates from the Hebrew to a civil calendar.

Sooner or later most Jewish genealogists confront the problem of date discrepancies, the phenomenon in which conflicting dates are used to record the same event in different records. Jewish genealogical researchers often require the use of two or more calendars (civil and Hebrew) for recording events and must convert dates from one calendar (for example, the Hebrew or Russian calendar) to another, the Gregorian (civil) calendar, in common usage in most of the world today.

A risk of error occurs whenever information is transmitted, and the more often information is transmitted, the greater the chances and size of error. In Jewish genealogy, faulty date conversion between the Hebrew calendar and the civil calendar(s) represents a potential source of error. Understanding the Luach and the conversion process may help to avoid or resolve these discrepancies. This article discusses divergent elements in multiple calendars and describes strategies used to unravel date problems.

Orientation

Records pertaining to Jews commonly involve date conversion. Most obvious are those that are dated in both Hebrew or Yiddish and civil calendars, such as tombstones and 19th-century Russian vital records. In truth, however, all unsupported date claims may have their source in date conversion. Prior to the mass migrations of the late 19th and early 20th centuries, most Jews primarily used the Hebrew calendar in recording dates. A Jew who lived in the world of the Luach recorded events according the Hebrew calendar, but typically also was required by his civil government to report dates according to the civil calendar. The Hebrew calendar was the source date; the civil date that appears in records created by ancestors from Eastern Europe often represents an inexact, bungled attempt at conversion. Experienced Jewish genealogists know, therefore, to view civil dates with skepticism and to treat them as approximations of the more reliable Hebrew date. In a case of a date discrepancy, the researcher must try to identify exactly where the conversion process failed and then reconvert properly to arrive at the correct date and, thus, resolve the discrepancy.

Date Conversion

Date conversion may be accomplished either with an electronic date conversion utility, such as a dual calendar, or without one. Although a utility conversion generally delivers results superior to a non-utility conversion, errors are possible: misapplied laws of conversion yield faulty dates. Like any tool, a converter is as accurate as the person who uses it. Knowledge of the calendar used and its rules are indispensable and are presented below.

Three calendars are in use today: solar, lunar, and luni/solar. The Gregorian and Julian are solar calendars; the Luach is a lunar-based calendar with solar adjustments or a luni/solar calendar. As its name implies, the solar calendar is governed by the sun. A year is measured by the time it takes the earth to complete one revolution around the sun, approximately 365 days. The year is divided into 12 months, 11 of which are composed of 30 or 31 days with one month (February) composed of 28 or 29 days in a leap year.

A pure lunar calendar, based solely upon the moon, has 12 months of 29 or 30 days, making the year approximately 354 days. This calendar is not linked to seasons, and the lunar year moves ahead of the solar, causing “seasonal drift.” To reconcile the lunar and solar calendars, the Hebrew luni/solar calendar adds a 13th month of 30 days seven times in a 19-year cycle.

Julian and Gregorian Calendars

The Gregorian calendar, as noted above, currently is used by most of the civil world; the Julian calendar and an older, Roman calendar variant were used in the Imperial Russian Empire until its dissolution in 1917. The Julian calendar, although similar to the Gregorian, lagged 12 days behind the Gregorian in the 19th century and 13 days in the 20th and 21st centuries.

Calendar Utility Conversion

To solve date discrepancies, three rules must be observed:

• Know which calendar was used.
• Use a reliable converter utility.
• Understand and employ the “plus one/minus one” rule.
  • A prerequisite to any date conversion is identification of the calendar used. A Gregorian date cannot be substituted for a Julian date, nor can a Julian date be substituted for a Gregorian date. The second rule, use a “reliable tool,” follows. We will demonstrate the conversion process with two calendars using Steve Morse’s calendar converter (see www.stephenmorse.org) but, without attention to detail, that site may not generate an accurate date.*
  • Case #1 involves the 1892 Russian birth record of Genakh Klotz (Henoch, later Henry Klotz) born in Telsiai, Lithuania on Iyar 4, 5652, which fell on April 19, 1892. But the Morse converter, when kept in default mode, converts Iyar 4 to May 1, 1892, not to April 19. The April date is not an error—rather, it was the Julian date, 12 days behind the Gregorian equivalent of May 1. When Henry Klotz came to the United States, he used April 19 and not May 1 as his birth date on an official record. This demonstrates that the original date recording system was retained by the immigrants in favor of adjustments to the new, prevailing date system.
  • The third rule is to use the “plus one/minus one rule” based on the following facts. A new Hebrew day or year always begins before a civil day (or year) because a Hebrew day begins at nightfall, while civil days begin at midnight. A new Hebrew year begins in September or October; a civil year begins on January 1. As a result, part of every civil day and year belong to the former or latter day or year of the Hebrew calendar.
  • Consider the observance of yahrzeit (anniversary of death) which begins at nightfall when the Hebrew day begins. A death that occurred during the period of time from nightfall until midnight will be recognized in the civil calendar as the same date as the preceding daylight period, whereas the Hebrew date will move ahead to the following day’s date. When a calendar conversion is made, the corresponding date reflects the bulk of the day. For the time from nightfall until midnight, however, one must apply the “plus one/minus one rule.” When converting from a civil to Hebrew date, add one; when converting from Hebrew to civil, subtract one. If this rule is disregarded, some dates will be wrong by a day.
  • “One off” errors are common in day, month, and year dates. It is useful to think in terms of “positive” and “negative” discrepancies. A positive discrepancy is a case in which apparently conflicting dates are confirmed to be in contradiction. A negative discrepancy is one in which no conflict exists between differing dates. Following are some examples.

Examples of Discrepancies

• The 1914 New York City tombstone of Joel Lapidus is an example of a turn-of-the-day positive discrepancy. This dual-dated tombstone gives death dates as December 13, 1914, and Kislev 24, 5685. Converting the dates in both directions (from civil to Hebrew and from Hebrew to civil) reveals that December 13 corresponds to Kislev 25, a discrepancy of one day from the Hebrew date that appears on the tombstone. At first glance, this appears to be a “false positive,” suggesting a nighttime death to explain the disparity.
• Further thought, however, reveals that the death could not have occurred at night. Had the death occurred at night on December 13, the Hebrew date would move ahead to Kislev 26, not backward to Kislev 24. If we now turn to the Hebrew date and convert in the opposite direction, Kislev 24 corresponds to December 12. Again, a nighttime death cannot explain the “one off” phenomenon, because moving backward, Kislev 24 actually starts the night of December 11. (Under the “plus one/minus one rule,” a nighttime conversion from a civil to a Hebrew date requires plus one; a Hebrew-to-civil conversion requires minus one.)
• This is a confirmed bona fide “positive” discrepancy. Which date is correct? Can they be reconciled? Three factors favor the Hebrew date:
• The mass migration of Eastern European Jews to the United Sates occurred between 1880 and the early 1920s.
• The tombstone date of 1914 suggests that the deceased and his family likely were immigrants and, thus, primarily used the Hebrew calendar.

• In 1914, Kislev 24 was Shabbat, and 24 Kislev is the eve of Chanukah. In all likelihood, these days would have been remembered. A distinct impression would have been made by a Shabbot death followed by the first night of Chanukah.
  • A copy of the New York City Health Department death record allows a test of this assumption. The record states that death occurred on December 12, 1914, at 4:00 p.m. The daytime death was, therefore, on Kislev 24 and suggests that the family primarily thought in terms of the Hebrew calendar. The December 13 date was wrong—but if the family had remembered the Hebrew date, why wasn’t December 12 used? The following scenario seems most likely. The death record indicates that the burial occurred on December 13. The family probably asked the undertaker (or cemetery office) for the civil date of death, and he gave the date on the record, which was the burial date. This date then was erroneously applied to the tombstone for the death date.
  • A second case, a late 20th-century (1998) tombstone of Ethel R. Krauss, is an example of a false positive. The death dates shown are November 19 and Kislev 1. In converting the civil date to the Hebrew date, one finds that November 19 was Cheshvan 30; the Hebrew date, when converted, yields November 20. Is this a “positive” discrepancy?” The death certificate reveals that the time of death was 8:01 p.m., which in November in New York City certainly was night. At night, the Hebrew date moves ahead, so in this case, the true Hebrew date was Kislev 1. Even though the dates do not match, there is no discrepancy.
  • Initially, both of the cases above seem to present discrepancies, but when the family’s familiarity and use of the Hebrew calendar orientation is factored in, both tombstones may be seen to be accurate. As a rule, one may expect this Hebrew calendar orientation in records of Jews who were born in Eastern Europe in the 19th and early 20th centuries and wherever families were traditional Jews in their lifestyle.
  • The May 28, 1954, Bronx, New York, death of Henry Regosin introduces additional layers of complexity about discrepancies. Two yahrzeit calendars (death anniversary schedule for subsequent years) were given to the relatives of the deceased, one from Bronx Memorials Corporation (a monument maker), which gave the Hebrew date as Iyar 25, and the other from Norman L. Jeffer Community Chapels, the funeral home, which showed May 28, 1954, p.m./Iyar 26 as the date of death. Which is correct?
• The Iyar 25 date is engraved on the tombstone made by Bronx Memorial. Converting May 28, 1954, to a Hebrew date, generates Iyar 25. The tombstone has no date discrepancy if death occurred in daylight, Iyar 25, but would be in error if death occurred at night, Iyar 26. Three considerations, however, favor the accuracy of the funeral home date the night of Iyar 26 and suggest an error on the tombstone:
• Proximity to the event: The undertaker rendered services closer to death than did the memorial corporation. (Tombstones are erected later.)
• Presumably, the funeral home is legally bound to obtain documentation (e.g., the death certificate) prior to taking custody of the body and must have date details. The tombstone company received its information from a family member at a later date.
• The funeral home record is more date specific, as it has the notation “p.m.” next to the date, which would explain a one-day ahead in the Hebrew calendar to Iyar 26. Consulting the death certificate for time of death might be one way to determine the correct yahrzeit date.
• Unfortunately, although the date, May 28,1954, was recorded in both sources, the exact time of death was not given. Like the funeral home yahrzeit calendar, only “p.m.” appears for time of death. If this were a nighttime death, the “p.m.” notation would explain a shift in date to the Iyar 26, but it does not prove it. Post meridiem (p.m.) simply means “afternoon” and is not the equivalent of nightfall in halacha (Jewish law) when the date moves ahead. How then can one determine time of death?
• In this case, the death certificate included a case number from the medical examiner. The file revealed tragic details of death from falling down a flight of stairs in the apartment building and includes information provided by the New York Police Department, Fordham Hospital, and the office of the Chief Medical Examiner. The Fordham Hospital record to the Chief Medical Examiner notes the arrival of Henry Regosin at 4:35 p.m. He was pronounced dead on arrival. His death was reported at 5:30 p.m., and the examiner was notified at 8:50 p.m. The answer is clear. Yes, it was “p.m.,” however, death occurred in the afternoon., not night. (Sunset for New York City on May 28, 1954, was 8:18 p.m. Daylight Standard Time.) Indeed, the date of death was Iyar 25.
• The medical examiner record lists death as May 28, 1954, p.m. This record likely was obtained by the funeral home, which interpreted “p.m.” incorrectly. This would explain the mistaken Hebrew date of Iyar 26 on the yahrzeit calendar. Although counterintuitive, the tombstone and family record are correct, while the “stronger” source, the funeral home, is not. Thus, the two yahrzeit calendars present a positive discrepancy, while the death certificate is deemed negative. This incident occurred on a Friday, erev (night before) Shabbat. The fact that the family retained the correct Hebrew date shows that it (the family) tended to record dates in terms of the Jewish calendar.
• The 1924 New York City tombstone of Abraham Krauss offers an example of a false negative. The date of death recorded on the tombstone was December 23, 1924/Teves 18, 5685. Converting these dates yields a perfect match. The official death record, however, gives the time of death as 11:00 p.m. If this was a nighttime death, then the Hebrew date moves ahead, making Teves 19 the correct yahrzeit. The Hebrew date on the tombstone should have appeared as Teves 19 instead of 18. The civil and Hebrew tombstone dates do match but, in this case, they should not. This is an example of a false negative.
  • It is important to distinguish here between primary and secondary sources, events, and dates. According to Princeton University, www.princeton.edu:

A primary source is a document or physical object which was written or created during the time under study. These sources were present during an experience or time period and offer an inside view of a particular event. A secondary source interprets and analyzes primary sources. These sources are one or more steps removed from the event.

• To this, we must add that one source may function as both primary and secondary. A primary source is primary for the primary event, but secondary for the secondary event. The event reported at the time of document creation is the primary event, while an event removed from the creation of the document is the secondary event. For example, the date of marriage in a marriage certificate is a primary source for the date of marriage, but secondary for the birthdays of the bride and groom. Secondary dates are based on testimony and are error prone, of which, we assert, faulty date conversion plays a significant part.

Associations with Jewish Holidays and Life Cycle Events

• Jewish holidays and life cycle events (such as births, marriages, and deaths, brit milah [circumcision], bar and bat mitzvah, yahrzeit) significantly influence records. Observant Jews may recall milestones with their Hebrew dates. Since the Jewish year is shorter than the civil year, and an extra month is added periodically as an adjustment, calendars do not neatly match up. Sometimes this discrepancy results in close to a full month’s difference between Hebrew and civil dates. If one does not use a utility conversion, imprecise estimations will occur, often substituting months based on associations. For example, say that September is associated with Rosh Hashanah. An individual accustomed to think of dates in terms of the Hebrew calendar and who performs a conversion without using a utility probably will convert the date to September, even when Rosh Hashanah falls in October.
• As is true with days, adjustments of one month ahead or behind, must be applied to misaligned months. Genealogists must place themselves in the shoes of the Hebrew calendar-oriented family member to determine the associations that likely caused the error. Only then can a seeming discrepancy be reconciled. Here is a bar mitzvah example:
• A turn-of-the-month example is the 1972 bar mitzvah of a boy born in 1960—but a bar mitzvah 12 years from birth? How can that be? The author was born on January 18, 1960, and celebrated his bar mitzvah on December 23, 1972. This may be understood as follows: The civil calendar begins in January, and the Hebrew, in Tishrei. Tishrei corresponds with September/October. This means that the Hebrew calendar, like the Hebrew day, moves ahead to the next year in the last third of the civil year. So, for example, most of 1972 corresponds to 5732. In September, however, the Hebrew calendar moved ahead to 5733. September through December, the last third of the civil year, belong to the following Hebrew year.
• In this case, the 1960 baby was born in Teves 5720, a year following a leap year. As such, Teves came late, in January. Thirteen years later, 5733 was a leap year. But Teves precedes the extra month and, therefore, was early, falling in December 1972 and not January 1973. In dealing with dates that come in the last third of a civil calendar year, when converting from Hebrew (5733) to the corresponding civil year (1973), subtract one from the civil year (=1972). When converting from civil (1972) to Hebrew (5732), add one year (=1973). Therefore, although short of the civil birthday of 1973, the bar mitzvah boy indeed was age 13 at his bar mitzvah in 1972 according to the Luach. This example shows that some problems only exist when one is oriented to a civil rather than Hebrew calendar.
• The birth date of Max Amdur, father of Sallyann Amdur Sack-Pikus, is an example of a positive discrepancy involving a change in months. As explained above, lunar months are shorter than solar; each solar month generally is composed of parts of two Hebrew months. For example, March may correspond with Adar and part of Nisan. Nisan will correspond with March and April. In a leap year, this may shift a month or so. Consequently, if one correlates months from one calendar to another, error is quite probable as is seen in this example. Max Amdur always believed that his birthday was March 23, 1910. Sallyann found his Sheboygan, Wisconsin, birth record, which stated his date of birth as April 23, 1910. Shown the document, Max maintained his position and attributed the discrepancy to a “late filing.” But, how could the record have been off by exactly one month to the day?
• Family lore preserved the details surrounding Max’s birth. He was born erev Pesach (the day before Passover). On that same day, following his delivery, Max’s mother got up out of bed to prepare the Seder meal for that night! With this information, Sallyann reasoned she could verify the correct date by converting erev Pesach of that year (5670) to the civil date in 1910. In those pre-Internet days, she did this by contacting the Hebraic division of the Library of Congress. The converted date was indeed April 23. What could have caused Max to have been off by a full month? Most likely this was “error by association.” The Amdur family preserved the date of birth according to the Hebrew calendar. Also, as relatively recent immigrants to the U.S., they may have retained the tendency to think of civil dates in terms of the Julian calendar. In the 19th century, the Julian calendar lagged 12 days behind the Gregorian calendar. As a result of this lag, 13 of the 19 years prior to and including the year of Max’s birth Jews observed Pesach during March, according to the Julian calendar. Clearly, for the Amdur parents, erev Pesach would be associated with March rather than April. On the rare occasion when Pesach fell in April, it was always at the beginning of the month. Therefore, the lateness in the month of Max’s birth (day 23) likely reinforced the parents’ association with the month of March. In other words, they remembered the day he was born (the 23rd) correctly, but remembered the month incorrectly.

Turn-of-the-Year Discrepancies

• Similar to the Jewish day and Jewish month, the Jewish year begins before the civil year. Rosh Hashanah, the Jewish New Year, is observed in September or October, while the civil year does not begin until January. Therefore, the last quarter or third of the civil year, when converted, belongs to the following Hebrew year. These disparities cause much confusion and “one off” discrepancies will frequently appear. The “plus one/minus one rule” also may be applied to year discrepancies, as we shall explain.
• The Hebrew calendar begins with Creation, “Anno Mundi” (a.m.) or “in the year of the world.” The current Hebrew year is 5771. This corresponds with 2010 in the civil calendar, however, this match holds true only for the majority of the year. The Hebrew year moves ahead one year with Rosh Hashanah (Jewish New Year). The last part of the civil year, from September (or October in some years) through December, belongs to the following civil year (e.g., 2011). Thus, one must employ the “plus one/minus one” rule from Rosh Hashanah in September/October through December. During this period, when converting from civil to Hebrew, add one year (September–December 2010 = Tishrei-Tevet 5771); for Hebrew to civil, subtract one year (Tishrei–Teves 5771= September–December 2010).
• The 1896 New York City marriage of Lena and Max Regosin and the 1897 birth of Herman A. Regosin illustrate a turn-of-the-year date discrepancy. According to the grandchildren, Max Ragosin (later Regosin) and Lea (Lena) Hertzberg married in 1896 in New York City, but no such record is found in the New York City vital records for this year. Fortunately, a surviving ketubah (marriage contract) recorded their marriage on the night of Teves 2, 5656 (December 18, 1895). Initially, one might consider a one-month civil calendar mix-up between December and January to account for a “one year off’ discrepancy. If Lena and Max were off by a month, December 1895 might have been remembered as January 1896.
• Further analysis, however, suggests that this was not the source of the error. The couple’s first child, Herman, claimed to have been born on October 22, 1897, but again the birth record appeared a year earlier, in 1896. Had Lena and Max thought that January 1896 was their marriage month, the October 1897 birth would have occurred almost two years after their marriage. Surely Lena and Max would not have forgotten a first birth occurring nine and a half months after their marriage and make their child’s birthday almost two years after marriage in 1896. (With nine months or so from a January marriage, it would have been conceivable for Herman to have been born in October 1896.) The more likely scenario would have been a correct memory of December with a mix-up in the year of marriage (between 1895 and 1896), which led to a mix-up with Herman’s year of birth (1896/7). A December 1896 marriage and an October 1897 birth, although both off by one year, would preserve the unforgettable nine-and-a-half month time span.
• A year’s discrepancy is commonplace, but we must ask what the reason is in this case? Taking the Hebrew-calendar-orientation approach, the scenario plays out like this: Surely, the Hebrew date would have been remembered. The couple celebrated their marriage on the night of Teves 2, 5656, the last night of Chanukah. Although the year 5656 began in 1895, most likely the Hebrew calendar-oriented couple forgot the “plus-one/minus-one” rule of subtracting one for a December date. Thus, they arrived at 1896. (This mistake threw off the subsequent birth record of Herman.) The New York City Health Department’s marriage record supports the Hebrew-orientation theory. On the opposite side of the marriage record, we find the signature of the bride, Lea (Lena) Hertzberg, signed in Yiddish. (As a recent immigrant, Lea could not write her name in English.) It is logical to assume that she recalled her Hebrew wedding date, but made a conversion error for the civil year.
• A second case deals with a missing 1893 birth record for Rachel Rogozin. After the death of World War I veteran Henry Klotz, his widow, Rae nee Rogozin/Regosin, attempted to collect the proceeds of a U.S. government insurance plan through the Veteran’s Administration. The Veteran’s Administration required proof of her birth. Rae was unable to produce a birth certificate, but instead, provided her father’s 1910 naturalization certificate. Listed on Jacob Rogozin’s 1910 naturalization certificate were his minor children, Rachel, age 16, and Dora, age 15. This was deemed insufficient proof of Rae’s birth on December 19, 1893. In lieu of a birth record or “church record of baptism,” two affidavits were required attesting to Rae/Rachel’s date of birth. Two cousins, Samuel Gitlin and David J. Rosen, provided acceptable testimony. They claimed Rachel Rogozin was born at 95 Ludlow St., New York City, to Lena (Lapidus) and Jacob Rogozin, and that her birthday “has been observed on December 19, 1893.” What was good enough for the Veteran’s Administration was unacceptable, however, to Rae’s genealogist grandson (this author).
• To solve the problem, assume that Hebrew orientation contributed to a mistaken civil date. Rather than dismiss the date as false, it is critical to look for the “kernel of truth” in it and to use that as a clue to arrive at the correct date. The task is to reconstruct the original Hebrew date from the mistaken civil date and to convert the Hebrew date back into the correct civil date. Keeping in mind that this does not represent an “accurate” conversion, one asks: “What Hebrew date is represented by December 19, 1893? What is the most common mistake made in the conversion process?” The answer is, the neglected “plus one/minus one rule.” The corresponding Hebrew year for most of 1893 is 5653. Because December belongs to the following Hebrew year, the rule is to add one. Here it is important to assume, however, that the plus-one/minus-one rule was ignored, so one would not add one and arrive at 5653.
• Next, ask what Hebrew month is associated with December? Kislev or Teves are the two months that correspond with December. Let us try Kislev 5653. Finally, what is the Hebrew date derived from 19? Keeping in mind we are not dealing with a precise conversion, it seems reasonable to assume that day 19 was not converted, but was simply carried over, as is, to the civil calendar. Now convert Kislev 19, 5653, back into the civil calendar. Kislev 19, 5653, when converted accurately, yields December 8, 1892. New York City birth record #46587 dated December 8, 1892, lists a “Rode” Rogozin born to Jacob Rogozin and Lena (Lapidus) at 95 Ludlow Street, New York City. Thus, by untangling a date discrepancy, the author explained his grandmother’s missing birth record.

Regosin family circa 1895.

• Having determined the birthday of Rae Regosin, one can extrapolate the date of a family studio portrait shown on the next page. The girl on the chair, Rae, born in December 1892, appears to be approximately three years old. The photograph can then be given a date circa 1895. The formal studio setting suggests that it was taken in honor of a special occasion. In light of a known, significant event that occurred that year in the Regosin family, namely the marriage of Jacob’s brother Max Regosin to Lena Hertzberg, one may tentatively assume, but cannot prove, the date of this portrait to be December 18, 1895, the date of Max and Lena’s marriage in New York City.

Summary

• We have reviewed the Hebrew and civil calendars with a focus on “one off” discrepancies in day, month, and year. Positive and negative discrepancies, positive, negative were explored. The strategy described here for solving date discrepancies may be summed up with the following, “Five Cs: convert, compare, correct, conciliate, and context. First, convert dates. Then compare to see if they concur and correct any error found. When possible, conciliate rather than eliminate. Ask if the mistake is truly an error, or rather a kernel (truth) buried in chaff (non-truth)? With the proper mindset, researchers can use a mistake as a clue to infer associations. Understood in the proper context, discordant dates can live in harmony, and finding elusive documents may become a reality.
• Note

*Stephen Morse has created an essential website for Jewish genealogists. Among his “One Step Pages,” one finds Hebrew/civil calendar conversion tools. Care must be taken when converting to observe the conversion rules.

This article is adapted from a presentation at the IAJGS conference in Los Angeles, July 2010—Ed.