Judaism
The Jewish calendar is fixed according to the number of years since the creation of the world (traditionally 3761 BCE. Thus the year 5000 began on 1 Sept. 1239 CE. When using the secular calendar, Jews use the terms BCE (before common era) and CE (common era) rather than BC and AD. The year follows a 354 day year of twelve lunar months. To harmonize this with the solar year of 365 1/4 days, an extra month, Adar II, is added into seven of every nineteen years. The months received Babylonian names during the
Exile
: Tishri (Sept./Oct.), Heshvan (Oct./Nov.), Kislev (Nov./Dec.), Tevet (Dec./Jan.), Shevat (Jan./Feb.), Adar (Feb./Mar.), Adar II (see above), Nisan (Mar./Apr.), Iyyar (Apr./May), Sivan (May/June), Tammuz (June/July), Av (July/Aug.), Elul (Aug./Sept.). The year begins with 1 Tishri, Rosh ha-Shanah.
A day begins and ends at sunset.
Rosh
ha-Shanah (the new year) is kept on 1 Tishri. It is followed by the days of repentance and Yom Kippur on 10 Tishri. The season of
Sukkot
(tabernacles) begins on 15 Tishri and concludes with Shemini Azeret (the Closing Festival) and
Sim
at Torah
(the rejoicing in the
law
) on 22/23 Tishri.
anukkah
(Lights) begins on 25 Kislev and ends on 2 Tevet. 10 Tevet is a fast day and 15 Shevat is the new year for trees.
Purim
(Lots, the Feast of Esther) is celebrated on 14 Adar. It is preceded by the Fast of Esther (13 Adar) and succeeded by Shushan Purim (15 Adar). Pesa
(
Passover
) begins on 15 Nisan and ends on 21/22 Nisan. 27 Nisan is Yom ha-Sho’ah (Day of the
Holocaust
) and 5 Iyyar is Israel Independence Day. Lag ba-Omer (the thirty-third day of the counting of the
omer
) is celebrated on 18 Iyyar and
Shavuot
(Pentecost) takes place on 6/7 Sivan. There are fast days on 17 Tammuz and 9 Av, and 15 Av is a minor holiday.
Christianity
The Julian calendar was reformed by Pope Gregory XIII in 1582 when it was realized that the Christian calendar was ten days in advance of the solar year. The reformed calendar is known as the Gregorian (or New) Style, the unreformed as the Julian (or Old) Style. The difference between the two calendars is now thirteen days, so that some Orthodox observe Christmas, 25 Dec. (Old Style), on 7 Jan. The Christian calendar follows each year the preparation for the coming of
Christ
, his life, death, and
resurrection
, and the being of God (see
FESTIVALS AND FASTS
). Thus, it begins with
Advent
, which has four Sundays, and then either one or two Sundays after Christmas bridge the gap to the
Epiphany
(6 Jan.). Thereafter ‘Sundays after Epiphany’ are reckoned until what used to be known as
Septuagisma
,
Sexagesima
, and
Quinquagesima
(Sundays before Lent); Ash Wednesday introduces the forty days of
Lent
, with its six Sundays; and five Sundays after Easter lead up to
Ascension
day with its following Sunday and
Pentecost
(Whitsunday). The remaining Sundays until Advent are numbered ‘after Trinity’ or ‘after Pentecost’. The Sundays of the Orthodox year fall into three segments:
triodion
(the ten weeks before Easter),
pentecostarion
(the paschal season), and
octoechos
(the rest of the year). See also
FESTIVALS AND FASTS
.
The system of dating years AD
(Lat., Anno Domini, ‘in the year of the Lord’) goes back to Dionysius Exiguus (‘the Small’;
c.
500–50). The abbreviations CE (Common Era) and BCE to replace AD and BC began with Jewish historians in the 19th cent., in order to avoid a religious confession within the words abbreviated.
Islam
The Muslim calendar is lunar, with twelve months of twenty-nine or thirty days. Because this is not adjusted to the solar calendar (contrast the Jewish system), the religious festivals and holidays advance around the seasons: thus the month of fasting,
Rama
n
, moves around the entire solar year, occurring sometimes in summer and sometimes in winter (intercalation is forbidden in the
Qur
n
9. 37). The months are: Mu
arram;
afr, Rab
‘ al-Awwal, Rab