18 votes
Accepted

What's the point of a haftorah for Miketz if it's always Shabbat Chanukah?

Actually, Miketz does not always fall out on Chanukah. It appears that whoever told me that was mistaken. :) I ran some code (using my JavaScript Hebcal API) and discovered that in the 100 years from ...
  • 22.9k
14 votes
Accepted

When is a convert's Hebrew birthday?

Dinonline answers, Although a Ger is considered to be “born anew” when becoming Jewish, this is a halachic concept that relates to family relationship and the like, and it is not a “biological ...
  • 12.8k
13 votes
Accepted

Does Passover occur on the first full moon after the equinox?

Your question and DoubleAA's comment on my original answer have inspired me to do some research and learn some really fascinating information about the Hebrew calendar. First, some background ...
  • 24.4k
13 votes

Changing the day of Shabbos?

While the Jewish holidays are controlled by the Sanhedrin (though, notably, they are not controlled by non-Jewish governments, and even the Sanhedrin's control is bound by divinely received rules), ...
  • 17.4k
12 votes
Accepted

Declare a leap year due to coronavirus?

There are two problems, both are discussed (among others) in Sanhedrin 11a. The first is that you need a Sanhedrin with a Nasi to intercalate a year. The second is that there are certain reasons for ...
  • 7,250
12 votes
Accepted

What is the א"ת ב"ש ג"ר calendar mnemonic?

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 ...
  • 18.8k
11 votes
Accepted

What are these marks with the numbers designating the Jewish years on this calendar?

They are a Gershayim, a Hebrew diacritic used in a number of ways, but generally to indicate that a certain set of letters does not spell a word in the ordinary sense. In this case, it is used to ...
  • 95.7k
11 votes
Accepted

Why do Kisidran years only occur when starting on a Tuesday or non-leap Thursday?

Modular arithmetic time: 385 mod 7 = 0 384 mod 7 = 6 383 mod 7 = 5 355 mod 7 = 5 354 mod 7 = 4 353 mod 7 = 3 That's how far Rosh Hashana moves from year to year. The Kisidran options are 4 and 6. ...
  • 95.7k
11 votes
Accepted

Date of the Akeida?

R. Yehuda Ayash points out that there are contradictory passages in the Zohar. In Parshat Vayikra it says that the Binding of Isaac took place on Rosh Hashanah, while in Parshat Vayeitzei it implies ...
  • 48.4k
10 votes
Accepted

Why some biblical holidays don't occur on certain days of the week?

The current fixed calendar is arranged (by adding or taking out an extra day in Marcheshvan or Kislev) such that Yom Kippur can't fall on Friday or Sunday (so there won't be two days in a row where no ...
  • 95.7k
10 votes
Accepted

Where do we first see Cheshvan (as opposed to Marcheshvan)?

Midrash Abba Gurion to Ester (ed. Buber 3:7), which was redacted in the tenth century, refers to it as חשוון (Heshvan): לתשרי זכות הרגלים, לחשוון זכות שרה It is also found in Eisenbach's edition ...
  • 35.1k
10 votes

Why was the calendar not arranged so that Yom Kippur never falls on Shabbat?

The fixed calendar already prevents Yom Kippur from falling on a Friday or Sunday, to avoid two consecutive days where all melachot are forbidden. (See Shulchan Aruch Orach Chaim 428:1 with e.g. Magen ...
  • 39.2k
10 votes

Declare a leap year due to coronavirus?

The rabbis currently do not have the authority to declare a leap year because there is no Sanhedrin. The current calendar was set up by Hillel II and is completely fixed by calculation. Indeed, even ...
  • 42.5k
9 votes
Accepted

Is there a best time of year to make aliya?

The best time? Get on the next flight. (listen to a clip of Gershon Veroba's song) But as for the most common/popular times to come: I am the research assistant (intern) on a study (currently ...
  • 22.9k
8 votes

Where in tanach are the months named

Just searching around in Torat Emet finds a few mentions of different months, in Tanach, besides for Adar: Nissan Esther 3:7 Nechemiah 2:1 Sivan Esther 8:9 Tammuz Yechezkel 8:14 (kidding) Elul ...
  • 18.8k
8 votes
Accepted

Why was there a huge concern to assure that Hoshanna Rabbah is not on Shabbat?

This priority is given in the Yerushalmi Sukkah 4:1: ר' סימון מפקד לאילין דמחשבין יהבון דעתכון דלא תעבדין לא תקיעתה בשבת ולא ערבתא בשבתא ואין אדחקון עבדון תקיעתה ולא תעבדון ערבתא R' Simon ordered ...
  • 1,657
8 votes

Is there a zero year in the ancient Jewish calendar?

Since the year begins at Rosh Hashanah, the number of the year changes then. Thus the year spans the secular year which changes in January. Thus this year (5776) started at Rosh Hashana 2015 and will ...
  • 42.5k
8 votes
Accepted

What is the greatest number of holiday days falling on weekdays in a year?

Between Purim and the next Shemini Atzeret the calendar is completely fixed (no leap years, leap days, etc.). The four possibilities are: Purim (F), Pesach (S-Sh), Shavuot (M), Tisha b'Av (S), Rosh ...
  • 95.7k
8 votes
Accepted

Why are some dates off by one day?

I think I may have discovered the answer. After mulling over the problem for a bit, I realized that not all cycles are created equally. The 19-year cycle just determines which years are leap years; it'...
  • 33.6k
8 votes
Accepted

Purim and Pesach in the same month

In 1999, the day of Purim fell out on the 2nd of March. This means that first few hours of pesach fell out on the 31st of March. Same happened in 1980, 1961.... The last time that Purim fell out on ...
  • 3,829
8 votes
Accepted

What is the source for Hillel’s having included an expiration date in the calendar?

You write that: It’s often said that when Hillel instituted the current calendar, he set an “expiration date” of 6000 AM; at that point the calendar would be invalid. Since Mashiach presumably will ...
  • 39.2k
8 votes
Accepted

Tisha b Av calendar confusion

This year the ninth day of the month of Av fell on Shabbat. Since fasting on Shabbat is forbidden, the holiday of Tisha b'av (which literally translates as "the Ninth of Av", hence the confusion) was ...
8 votes

Why does the date for the prayer for rain change from one century to the next?

The rules try to keep the date for requesting rain in the late fall. They are not perfect. No rule would be except adding the ever-changing long decimal tropical year length. If we were to take a ...
  • 95.7k
8 votes

What did people say in Shemoneh Esrei and Kiddush of Shavuos when it didn't fall out on the 6th of Sivan?

Two basic answers exist to this question: In reality, when the calendar was decided by testimony of the new moon, this phrase probably did not exist in the prayers. Maseches Sofrim 19:4 writes: ...
8 votes
Accepted

Historical Daf Yomi calendar

I have found that Daf Yomi Calendar has the calendar for cycles 11 - 15. This site does not have any earlier cycles. I have found D.A.F.'s Talmud Tools which allows you to search back by Daf, Hebrew ...
  • 42.5k
7 votes

Is it heresy to follow secular dating on the destruction of the first Temple?

R. H. Shachter notes in a shiur here (beginning at minute 66)1 that the Baal HaMeor seems to have embraced the secular chronology (to the ire of the Raavad) and added that Chazal's fallibility is ...
  • 35.1k
7 votes

Looking for a Niddah Calendar calculator

Try https://www.mymikvahcalendar.org which has approbations from 7 Rabbis, 1 institution and 3 Kallah teachers. The FAQ also talks about the settings menu so it may have options to customize whether ...
7 votes

How often does Addar II happen?

The extra Adar happens when there is a leap year -- we add a month to preserve the lunar properties of the calendar. Seven in nineteen years are leap years, so every 2-3 years on average. From ...
7 votes
Accepted

Why is there never a break between parshiot Parah and Hachodesh?

The Aruch Hashulchan in OC 685 says that there are no breaks between them because they are related to each other (unlike the others, which are unrelated to the ones next to them, meaning that Zachor ...

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