Jewish holidays

Jewish holidays, also known as Jewish festivals or Yamim Tovim, are holidays observed by Jews throughout the Hebrew calendar. They include religious, cultural and national elements, derived from four sources: mitzvot, rabbinic mandates, the history of Judaism, and the State of Israel.
Jewish holidays occur on the same dates every year in the Hebrew calendar, but the dates vary in the Gregorian. This is because the Hebrew calendar is a lunisolar calendar, whereas the Gregorian is a solar calendar. Each holiday can only occur on certain days of the week, four for most, but five for holidays in Tevet and Shevat and six for [|Hanukkah].

Holiday	Date range
[\|Rosh Hashanah]	5 Sep to 5 Oct
[\|Yom Kippur]	14 Sep to 14 Oct
Sukkot	19 Sep to 19 Oct
[\|Shemini Atzeret]	26 Sep to 26 Oct
Simchat Torah	27 Sep to 27 Oct
Hanukkah	28 Nov to 27 Dec
Tu Bishvat	15 Jan to 13 Feb
[\|Purim]	24 Feb to 26 Mar
Shushan Purim	25 Feb to 27 Mar
Pesach	26 Mar to 25 Apr
Yom HaShoah	8 Apr to 7 May
Yom Ha'atzmaut	15 Apr to 15 May
Lag B'Omer	28 Apr to 28 May
Yom Yerushalayim	8 May to 7 Jun
[\|Shavuot]	15 May to 14 Jun
Tzom Tammuz	25 Jun to 25 Jul
Tisha B'Av	16 Jul to 15 Aug
Tu B'Av	22 Jul to 21 Aug

General concepts

Groupings

Certain terms are used very commonly for groups of holidays.

The Hebrew-language term Yom Tov, sometimes referred to as "festival day", usually refers to the six biblically mandated festival dates on which all [|activities prohibited on Shabbat] are prohibited, except for some related to food preparation. These include the first and seventh days of [|Passover], Shavuot, both days of Rosh Hashanah, first day of Sukkot, and Shemini Atzeret. By extension, outside the Land of Israel, the second-day holidays known under the rubric Yom tov sheni shel galuyot —including Simchat Torah—are also included in this grouping. Colloquially, Yom Kippur, a biblically mandated date on which even food preparation is prohibited, is often included in this grouping. The tradition of keeping two days of Yom Tov in the diaspora has existed since roughly 300 BCE.
The English-language term High Holy Days or High Holidays refers to Rosh Hashanah and Yom Kippur collectively. Its Hebrew analogue, "Days of Awe", is more flexible: it can refer just to those holidays, or to the [|Ten Days of Repentance], or the entire penitential period, starting as early as the beginning of Elul, and ending as late as Shemini Atzeret.
The term Three Pilgrimage Festivals refers to Passover, Shavuot and Sukkot. Within this grouping, Sukkot normally includes [|Shemini Atzeret and Simchat Torah].
Ma'agal Hashana, a more general term, is often used – especially in educational settings – to refer to the overall study of the Jewish calendar, outlining the month by month events, with mitzvot and minhagim, and philosophical material, that occur over the year.
Terminology used to describe holidays

Certain terminology is used in referring to different categories of holidays, depending on their source and their nature:
[|Shabbat] , or Sabbath, is referred to by that name exclusively. Similarly, [|Rosh Chodesh] is referred to by that name exclusively.

Yom tov : See "Groupings" [|above].
Moed , plural moadim, refers to any of the Three Pilgrimage Festivals of Passover, Shavuot and Sukkot. When used in comparison to Yom Tov, it refers to Chol HaMoed, the intermediate days of Passover and Sukkot.
Ḥag or chag , plural chagim, can be used whenever yom tov or moed is. It is also used to describe Hanukkah and Purim, as well as Yom Ha'atzmaut and Yom Yerushalayim.
Ta'anit, or, less commonly, tzom, refers to a fast. These terms are generally used to describe the rabbinic fasts, although tzom is used liturgically to refer to Yom Kippur as well.
"Work" on Sabbath and biblical holidays

The most notable common feature of Shabbat and the biblical festivals is the requirement to refrain from the 39 Melakhot on these days. Melakha is most commonly translated as "work"; perhaps a better translation is "creative-constructive work". Strictly speaking, melakha is defined in halakha by 39 categories of labor that were used in constructing the Tabernacle while the Jews wandered in the desert. As understood traditionally and in Orthodox Judaism:

On Shabbat and Yom Kippur all melakha is prohibited.
On a holiday other than Yom Kippur which falls on a weekday, not Shabbat, most melakha is prohibited. Some melacha related to the preparation of food is permitted.
On weekdays during Chol HaMoed, melakha is not prohibited per se. However, melakha should be limited to that required either to enhance the enjoyment of the remainder of the festival or to avoid great financial loss, or several other categories.
On other days, there are no restrictions on melakha.

In principle, Conservative Judaism understands the requirement to refrain from melakha in the same way as Orthodox Judaism. In practice, Conservative rabbis frequently rule on prohibitions around melakha differently from Orthodox authorities. Still, there are some Conservative/Masorti communities around the world where Shabbat and festival observance fairly closely resembles Orthodox observance.
However, many, if not most, lay members of Conservative congregations in North America do not consider themselves Shabbat observant, even by Conservative standards. At the same time, adherents of Reform Judaism and Reconstructionist Judaism do not accept traditional halakha, and therefore restrictions on melakha, as binding at all. Jews fitting any of these descriptions refrain from melakha in practice only as they see fit.
Shabbat and holiday work restrictions are always put aside in cases of pikuach nefesh, which are actions to save a human life. At the most fundamental level, if there is any possibility whatsoever that action must be taken to save a life, Shabbat restrictions are set aside immediately, and without reservation. Where the danger to life is present but less immediate, there is some preference to minimize violation of Shabbat work restrictions where possible. The laws in this area are complex.

Second day of biblical festivals

The Torah specifies a single date on the Jewish calendar for observance of holidays. Nevertheless, festivals of biblical origin other than Shabbat and Yom Kippur are observed for two days outside the land of Israel, and Rosh Hashanah is observed for two days even inside the land of Israel.
Dates for holidays on the Jewish calendar are expressed in the Torah as "day x of month y". Accordingly, the beginning of month y needs to be determined before the proper date of the holiday on day x can be fixed. Months in the Jewish calendar are lunar, and originally were thought to have been proclaimed by the blowing of a shofar. Later, the Sanhedrin received testimony of witnesses saying they saw the new crescent moon. Then the Sanhedrin would inform Jewish communities away from its meeting place that it had proclaimed a new moon. The practice of observing a second festival day stemmed from delays in disseminating that information.

Rosh Hashanah. Because of holiday restrictions on travel, messengers could not even leave the seat of the Sanhedrin until the holiday was over. Inherently, there was no possible way for anyone living away from the seat of the Sanhedrin to receive news of the proclamation of the new month until messengers arrived after the fact. Accordingly, the practice emerged that Rosh Hashanah was observed on both possible days, as calculated from the previous month's start, everywhere in the world.
Three Pilgrimage Festivals. Sukkot and Passover fall on the 15th day of their respective months. This gave messengers two weeks to inform communities about the proclamation of the new month. Normally, they would reach most communities within the land of Israel within that time, but they might fail to reach communities farther away. Consequently, the practice developed that these holidays be observed for one day within Israel, but for two days outside Israel. This practice is known as yom tov sheni shel galuyot, "second day of festivals in exile communities".

Yom Kippur is not observed for two days anywhere because of the difficulty of maintaining a fast over two days.
Adherents of Reform Judaism and Reconstructionist Judaism generally do not observe the second day of festivals, although some do observe two days of Rosh Hashanah.

Holidays of biblical and rabbinic (Talmudic) origin

Shabbat—The Sabbath

Jewish law ' accords Shabbat the status of a holiday, a day of rest celebrated on the seventh day of each week. Jewish law defines a day as ending at either sundown or nightfall, when the next day then begins. Thus,
Shabbat begins just before sundown Friday night. Its start is marked by the lighting of Shabbat candles and the recitation of Kiddush over a cup of wine.
Shabbat ends at nightfall Saturday night. Its conclusion is marked by the prayer known as Havdalah.
The fundamental rituals and observances of Shabbat include:
Reading of the Weekly Torah portion
Abbreviation of the Amidah in the three regular daily services to eliminate requests for everyday needs
Addition of a musaf service to the daily prayer services
Enjoyment of three meals, often elaborate or ritualized, through the course of the day
Restraint from performing melacha.
In many ways, halakha sees Shabbat as the most important holy day in the Jewish calendar.
It is the first holiday mentioned in the Tanakh, and God was the first one to observe it.
The Torah reading on Shabbat has more sections of parshiot than on Yom Kippur or any other Jewish holiday.
The prescribed penalty in the Torah for a transgression of Shabbat prohibitions is death by stoning, while for other holidays the penalty is less severe.
Public observance of Shabbat is the benchmark used in halacha to determine whether an individual is a religiously observant, religiously reliable member of the community.
Arbah Parshiyot
There are four Sabbaths, all during or in proximity to, the month of Adar, which have special significance because of additions which are made during the Torah reading on those days. These include:
Parshat Shekalim: the Shabbat either preceding or coinciding with Rosh Chodesh Adar. The portion that is read describes the half-shekel that was brought during Adar.
Parshat Zachor: the Shabbat immediately preceding Purim. The passage that is read describes the commandment to remember the actions of Amalek.
Parshat Parah: the Shabbat immediately following Purim. The additional Torah portion describes the ritual of the red heifer.
Parshat Hachodesh: the Shabbat preceding Rosh Chodesh Nissan. The portion read describes the commandment to recognize Nissan as the first of the Hebrew months.
Other Special Sabbaths'
Other Sabbaths throughout the year are considered specially significant because of the time of year or the Torah portion and/or Haftorah being read. Shabbat Shuva is the Shabbat preceding Yom Kippur and Shabbat Hagadol is the Shabbat preceding Pesach. On both of these it is customary for the rabbi of the synagogue to give an extended lecture on a topic related to the upcoming holiday. Shabbat Bereishit is the Shabbos immediately following Simchat Torah, in which the yearly Torah-reading cycle restarts anew. Shabbat Shira is the Shabbos on which the Shirat Hayam is read as part of Parshat Beshalach; it is customary to leave out breadcrumbs before this Shabbos for wild birds to eat. Shabbat Chazon is the Shabbos preceding Tisha b'Av, during which the ominous haftorah of Chazon Yishayahu is read. Shabbat Nachamu is the Shabbos following Tisha b'Av during which the consolatory haftorah of Nachamu Ami is read. The Shabbat preceding every Rosh Chodesh is known as Shabbat Mevorochim''; a prayer is added to the liturgy in anticipation of the coming month.