Days of week on Hebrew calendar

The modern Hebrew calendar has been designed to ensure that certain holy days and festivals do not fall on certain days of the week. As a result, there are only four possible patterns of days on which festivals can fall. (Note that Jewish days start at sunset of the preceding day indicated in this article.)

Hebrew week days

Reasons

The modern Hebrew calendar has been arranged so that Yom Kippur does not fall on a Friday (Yom Shishi) or Sunday (Yom Rishon), and Hoshana Rabbah does not fall on Shabbat.^[1] These rules have been instituted because Shabbat restrictions also apply to Yom Kippur, and if Yom Kippur were to fall on Friday (Yom Shishi), it would not be possible to make necessary preparations for Shabbat, including candle lighting, because the preceding day is Yom Kippur. Similarly, if Yom Kippur fell on a Sunday (Yom Rishon), it would not be possible to make the necessary preparations for Yom Kippur, including candle lighting, because the preceding day is Shabbat.^[2] Also, the laws of Shabbat override those of Hoshana Rabbah (the seventh day of Sukkot), so that if Hoshana Rabbah were to fall on Shabbat certain rituals that are a part of Hoshana Rabbah services (such as carrying willows, which is work) could not be performed in that year.

As a consequence, in the case of Yom Kippur, which falls on 10 Tishrei and cannot fall on a Friday or Sunday, the days in Cheshvan and/or Kislev are adjusted so that Rosh Hashanah, which falls on 1 Tishrei, does not fall on a Wednesday (Yom Revii) or Friday (Yom Shishi). And, in the case of Hoshana Rabbah, which falls on 21 Tishrei and cannot fall on a Saturday, Rosh Hashanah cannot be on a Sunday. This leaves only four days on which Rosh Hashanah is allowed to fall: Monday, Tuesday, Thursday and Saturday (i.e. the first, second, or fourth days of the week, or Shabbat), which are also referred as the "four gates" (Hebrew: ארבעה שערים, romanized: arba'a shearim).

The four gates

Since three arrangements cannot occur within the fixed calendar, most holidays can each occur on one of four possible days.

All the holy days and festivals fall in the months of

The period from 1 Adar (or Adar II, in leap years) to 29 Cheshvan contains all of the festivals specified in the Bible -

• Neither the Three Pilgrimage Festivals nor Rosh Hashanah coincide with the Sabbath nor fall on Sunday, therefore no additions to the Yom Tov kiddush (i.e. the Sabbath additions and havdalah) are said during the course of the year.
• Since Purim falls on Sunday, the 13th of Adar, known as the Fast of Esther, falls on Saturday. Usually, fasts other than Yom Kippur are postponed to the following Sunday. But as this Sunday is Purim, and fasts are usually not observed on Friday, the fast is advanced to the prior Thursday (the 11th of Adar).
• This is the only instance in which there is
  a Sabbath of Chol HaMoed
  for both Passover and Sukkot.
• Yom HaZikaron is postponed from Sunday to Monday, and Yom Ha'atzmaut is postponed from Monday to Tuesday, so that preparations cannot interfere with Shabbat.
• No leniencies are made for the observance of Tisha B'Av nor the Tenth of Av.
• During Tishrei, three holidays start on Thursday. In the diaspora, the eruv tavshilin is prepared thrice. (In Israel, it is only made on the eve of Rosh Hashanah.)
• In Israel, this is the only occasion with a "three-day holiday" (the two days of Rosh Hashanah followed by the Sabbath).
• Due to immediately following Rosh Hashanah, an abridged form of
  Shabbat Shuvah
  .
• The
  Fast of Gedaliah falls on Saturday. Since fasts other than Yom Kippur are not observed on Saturday, this is observed on the following Sunday. This leaves an interval of just five days between fasts, the shortest ever on the Jewish Calendar (other than the Fast of Behav
  ).
• Vayehi Noam and V'Ata Kadosh are recited on Motza'ei Shabbat Shuvah, due to their occurrence being exactly one week before Yom Kippur.
• Ashkenazim recite Avinu Malkeinu on the eve of Yom Kippur, due to it largely being omitted on Yom Kippur itself.
• Yom Kippur occurs on Saturday. This is the only occurrence in which a fast is ever observed on Saturday. Ashkenazim do not recite Avinu Malkeinu except during Ne'ila.
• This is the only instance in which Bereshit is not read during the Torah reading on the preceding Thursday.
• If the previous gate was also 1, this is a leap year; and, Nitzavim-Vayelech are the only doubled-up parshiot during the year (Tishrei-Elul).
• If this is a leap year and the previous gate was 2, the following occur:
  • According to the custom that the
    Shabbat HaGadol
    (Gate 1-1 and Gate 4).
  • Tazria's proper haftarah is read.
• If the previous gate was 3, this is not a leap year.
• If Cheshvan has 29 days, then Kislev will have either 29 or 30 days. This is the only occurrence in which it happens.
• If both Cheshvan and Kislev have 30 days, then the Tenth of Tevet will occur on Friday, one of two public fasts that can possibly be observed on a Friday (the other being the Fast of the Firstborn). The fast is not broken until nightfall, after the Sabbath begins.
• If both Cheshvan and Kislev have 30 days, then Purim Katan, the holiday that only occurs in leap years, will occur on Friday.

Gate 2 (28.6%)

• The eruv tavshilin is prepared prior to the first day Passover in the diaspora and prior to Shavuot in both the diaspora and Israel.
• Yom HaZikaron and Yom Ha'atzmaut are actually observed on 4 Iyar and 5 Iyar respectively.
• Balak. To compensate for this, Chukat
  -Balak are doubled up in the diaspora. (In Israel, these two parshiot are always read separately.)
  • In the diaspora, the usual Torah reading of the second day of Shavuot (Deuteronomy 15:19–16:17) is extended to its length on Shemini Atzeret (Deuteronomy 14:22–16:17) to accommodate the seven readings on the Sabbath.
• Following Tisha B'Av, bathing, laundering, shaving, and taking a haircut are all permitted immediately after the fast, in preparation for the Sabbath. These, along with the rest of the restrictions of the Nine Days, are normally postponed until midday on the Tenth of Av.
• Rosh Hashanah,
  Four Species
  , which are not taken on the Sabbath, are unused on the first day.
• This is the only instance in which no day of
  the Sabbath of Chol HaMoed
  , is thus read on the first day of Sukkot in Israel and on Shemini Atzeret in the diaspora.
• In the diaspora, the first reading from the Torah on Shemini Atzeret (Deuteronomy 14:22–15:23) is split into three readings (i.e. the same readings as when yom tov sheni shel galuyot for the last day of Passover and for Shavuot coincide with the Sabbath) to accommodate the seven readings on the Sabbath.
• In Israel, Simchat Torah, as it always coincides with Shemini Atzeret in Israel, falls on Saturday, the only time Simchat Torah ever falls on Saturday. (In the diaspora, Simchat Torah never occurs on Saturday.)
  • In communities where the Torah is read at Maariv on Simchat Torah, this is the only occurrence of the Torah being read during Maariv, Shacharit and Mincha on the same day.
  • This is also the only instance in which Bereshit is read during the Torah reading of Saturday afternoon.
• This is the only instance in which Bereshit is read during the during the Torah reading on the preceding Monday (in both the diaspora and Israel).
• If the previous gate was also 2, this is a leap year.
  • If this is a leap year, then Tazria's proper haftarah is read.
• If the previous gate was 4, this is not a leap year.
• The Sabbath of Vayeshev falls during Hanukkah (this is the only case in which this occurs) and one of two uncommon haftarot is read for Miketz:
  • If both Cheshvan and Kislev have 29 days, Hanukkah will begin on Friday and the Sabbath of
    haftarah
    will thus be read).
  • If both Cheshvan and Kislev have 30 days, Hanukkah will begin and end on the Sabbath and the haftarah for Vayakhel (which is only read in leap years when the preceding gate was 1) is read for Miketz.
• If both Cheshvan and Kislev have 29 days, then the Tenth of Tevet will occur on Friday, one of two public fasts that can possibly be observed on a Friday (the other being the Fast of the Firstborn). The fast is not broken until nightfall, after the Sabbath begins.
• If both Cheshvan and Kislev have 30 days, then
  Tu Bishvat will occur on Saturday. This means that on Rosh Chodesh Shevat, two Torah scrolls are used for the Sabbath morning Torah reading: one for Va'eira
  and one for Rosh Chodesh.
• If both Cheshvan and Kislev have 29 days, then Purim Katan, the holiday that only occurs in leap years, will occur on Friday.