12

The Shulchan Aruch 428:3 explains the mnemonic: סימן לקביעת המועדים א"ת ב"ש ג"ר ד"ק ה"ץ ו"ף פירוש ביום א' של פסח יהיה לעולם ת"ב וסימן על מצות ומרורים יאכלוהו ביום ב' בו שבועו' וביום ג' בו ר"ה ביום ד' בו קריאת התורה שהוא שמחת תורה ביום ה' בו צום כיפור ביום ו' בו פורים שעבר: The way it works is the first letter of the ...


7

This opinion of R. Sa'adia Ga'on is quoted by R. Avraham b. Hiyya HaNasi. In his Sefer Ha-Ibbur, he writes (ma'amar sheni, sha'ar shemini): ואמר הגאון ר' סעדיה בר' יוסף ראש הישיבה זצ"ל: קבוע היה מהר סיני שלא יהיה פסח יום שני כדי שלא יהיה יום הכפורים ערב שבת... וכן אם היה פסח יום רביעי היה יום הכפורים יום ראשון... וכן אנו אומרים על פסח שאינו ביום ששי ...


6

I won't answer the question as stated. Instead I will address one premise of the question, which is actually very common with this type of question. The question assumes that Pesach is supposed to be at the time of the regular barley harvest. This come from a mistaken understanding of the Torah. The connection between Pesach and the barley harvest is from ...


4

14 Nissan. You are right to notice that Hebrew dates and English dates never match exactly, because our day begins at sundown and English dates go by midnight. However, calendars go by the daylight where there is most of the overlap, and ignore the few hours difference.


4

Here's a screenshot of part of an excel calendar that I made a while ago, which answers your question:


4

Pay close attention to the dates you're submitting: 26 Elul 5777 is 17 September 2017 (true) 27 Elul 5777 is 18 September 2017 (true) 27 Elul 5778 is 7 September 2018 (true) 21 September 2017 is 1 Tishrei 5778 (true) Here is 26 Elul 5777 as an annotated screenshot: What it has at the top of the page is correct. It's what's in the box next to the "...


3

The epoch of the current calendar is, as you point out, BaHaRaD - Monday, 5 hours and 204 chalakim. However, it’s crucial to realise that this is an artificial date, arrived at by winding the calendar backwards, and corresponds to the molad of Tishrei of Year 1. It is referred to as molad tohu. This is almost an entire year before the world was created on ...


3

The rules you mention in your question are supposed to give a date 60 days after the autumnal equinox as the start date for requesting rain, following the practice in Babylon during Talmudic times. As noted in @DoubleAA’s answer, the current system is based on the ‘tekufah of Shemuel’ which assumes a mean solar year of 365.25 years, causing a slight drift ...


3

In Genesis, the seventh day of creation was the first Sabbath. Ever since then, every seventh day has been a Sabbath.


3

If you have access to the internet for a little while, you can download my video where I go through the entire calculation. Video course on Jewish Calendar. There are software tools available there (calculator, web page for the Tur's keviyuyos) that are helpful as well. You could do it with pencil and paper after watching that - I admit that I didn't! I'm ...


2

In the Cairo Genizah a fragment of a midrash was discovered that, among other things, lists the birthdays of the shevatim. Ezra Chwat from the National Library of Israel transcribed the midrash and added footnotes comparing other sources (can be found here): Reuven - 14th to the 9th month - 14th of Kislev Shimon - 21st to the 10th month (28th according to ...


2

The word צח "Tzach" occurs in Isaiah 18:4 and Jeremiah 4:11, and some have proposed that it is a Canaanite month name, but Jerome does not so translate, neither does the RSV. They thought they found support for this theory in one of the Arad ostraca, but the ostracon has since been re-interpreted. (Jan A. Wagenaar, Origin and Transformation of the ...


2

I wrote a program using scripts I wrote for TorahCalc that will calculate when this will happen. Having it end up on the exact date is very rare. Here are the dates for the next 1,000 years where Nissan 14 will be the last day of the masechta: Mon Mar 31 2064 / Nissan 14 5824 - Kerisus 28 Mon Apr 24 2119 / Nissan 14 5879 - Kesuvos 112 Wed Apr 23 2138 / ...


2

The Qumranites included priests, "Sons of Zadok" among their number, if the Community Rule (1QS) is an accurate reflection of actual practice. I think that they expected that their philosophy would eventually rule in the Temple. The War Scroll (1QM) describes "years of remission" when the war against the "Sons of Darkness" ...


2

In the Babylonian calendar, which Jews used in the late pre exilic, exilic, and early post exilic periods, the 1st of Nisannu always fell after what we would consider to be the equinox (though not necessarily after the equinox as the Babylonians counted it.) By the Herodian period, it is not certain that Judea is following Babylon any more. Josephus says ...


1

According to this answer on Hidabroot, it's the first Adar that has the mazal of Dagim. The question should be what mazal the second Adar has. The answerer suggests that the reason that Dagim is plural rather than singular (dag) is because it can cover both months. However, there are views that the second Adar doesn't have a mazal at all (more sources can be ...


1

This is discussed in Mishnah Rosh Hashanah 2:2 Initially, after the court sanctified the new month they would light torches on the mountaintops, from one peak to another, to signal to the community in Babylonia that the month had been sanctified. After the Samaritans [Kutim] corrupted and ruined this method by lighting torches at the wrong times to confuse ...


1

Nitei Gavriel Aveilus2 75:1:1 brings the following sources for Yarzheit candles. Minhagei Vermaisha Volume 2, Page 112 Maharshal Chapter 46 Magen Avraham 261:6 Nachalas Shiva Chapter 73 Kitzur Shulchan Aruch 221:1 Mishmeres Shalom Note 10:10 Gesher HaChaim 32:4 Will try to add more customs and sources later.


1

The mathematical part of the Rabbinic calendar was developed in the period C.E. 700-950. (Sacha Stern, Calendar and Community Oxford University Press 2001.) It was not known to Moses.


1

To quote from Wikipedia: The Jewish calendar is based on the Metonic cycle of 19 years, of which 12 are common (non-leap) years of 12 months and 7 are leap years of 13 months. To determine whether a Jewish year is a leap year, one must find its position in the 19-year Metonic cycle. This position is calculated by dividing the Jewish year number by 19 and ...


1

In the Babylonian calendar, which Jews used in the late pre-exilic, exilic, and early post-exilic periods, the month of Nisanu always began after the equinox by our definition, though not always by the Babylonians' definition. In the Herodian period, according to Josephus, it is the 14th of Nisan that falls on or after the equinox: In the month of Xanthicus,...


1

An excellent work, written by a major Torah authority but geared for the layman, is "The Jewish Calendar: It Structures and Laws" by Rav David Feinstein. From the Product description (linked above): When the Syrian-Greeks - in the time of Chanukah - wanted to undermine and eventually destroy Jewish life, one of the three commandments they tried to ...


1

If "yrh" in the Gezer calendar means a lunar month, then the calendar must have been intercalated periodically or the agricultural activities would have fallen out of synchronization with the months. There is always the possibility that it describes a solar calendar like the Egyptian calendar. This calendar did not have a fixed relationship to the ...


1

In his Corona responsum, Rabbi Hershel Schachter cites Rabbi Soloveitchik zt"l that requests, including please give us rain, can be made of G-d at whatever point is appropriate; however, Mashiv HaRuach UMorid HaGeshem is describing G-d's greatness. The individual is not authorized to change such descriptions willy-nilly, and thus a communal announcement is ...


1

The meaning of סוד העיבור in the Talmud is "Council of Intercalation". Sacha Stern, Calendar and Community, Oxford University Press, 2001, p. 190. It refers to the calendrical court. The meaning "secret of intercalation" arose later.


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