The Julian Calendar is a solar calendar proposed by Julius Caesar and standardized by Augustus. It was modeled on the ancient Egyptian civil calendar.
A normal Julian year has 365 days while leap years, which occur every 4 years, add an additional day to the month of February. No other intercalations are made.
1 January marks the start of a Julian year. By convention, dates before the
Gregorian Calendar reform of 1582 CE
are reported in the Julian Calendar.
A Julian day begins at midnight.
A.M. – Anno Mundi. This calendar was used by several of the Byzantine authors including Theophanes and Anastasius Bibliothecarius. The calendar is based on the Julian calendar however the year does not begin on 1 January and the starting day, month, and year of this calendar was a point of contention as it was based on an estimate for the start of "creation" (among other things) as interpreted through the Septuagint - a Greek translation of the Old Testament. An ongoing several hundred year long theological debate over when Biblical "creation" began led to multiple versions of the A.M. calendar. The earlier Byzantine sources used the Alexandrian version (A.M.a) or “Alexandrian era” of this calendar which has a starting date of 25 March 5492 BCE or, according to Bickerman (1980), 25 March 5493 BCE. Earthquake catalogers Guidoboni et al (1994) and Ambraseys (2009) assume a starting date of 25 March 5492 BCE and that is what I use. As explained by Grumel (1958:219)
The Alexandrian era of Panodorus began in 5493 BCE [and] the Alexandrian era of Annianos began in 5492 BCE. The Alexandrian Era of Annianos is what is commonly called the Alexandrian era.Another reckoning system, used for example by Megas Chronographos, is the Byzantine version (A.M.Byz) which has a starting date of 1 September 5509 BCE (Bickerman, 1980:73-74). Yet another reckoning system is a variant suggested in Chronicon Paschale which was composed in ~630 CE. The starting date for this system is 21 March, 5507 BCE. In the Anno Mundi calendar system used by the Byzantine authors, the day followed the Roman civil custom of beginning the calendarical day at midnight. When hours are indicated they mark time since dawn. Hence, if daybreak began at 6 am, the 4th hour would correspond to 10 am (Rautman, 2007:3).
|Theophanes||Grumel (1934:407), Proudfoot (1974:373-374), and others have pointed out that Theophanes A.M.a in the years A.M.a 6102-6206 and A.M.a 6218-6265 are frequently a year too low.|
Indictions - An indiction (Latin: indictio, impost) was a periodic reassessment of taxation in the Roman Empire which took place every fifteen years.
In Late Antiquity, this 15-year cycle began to be used to date documents and it continued to be used for this purpose in Medieval Europe. Indictions
refer to an individual year in the 15 year cycle; for example, "the fourth indiction" came to mean the fourth year of the current indiction. Since
the cycles themselves were not numbered, other information is needed to identify the specific year. When an ancient author supplies an indiction along
with an A.M. date, the result may be greater chronological precision. For our dating purposes, indictions began in 312 CE when they were introduced by the Roman Emperor
Constantine. The indiction was first used to date documents unrelated to tax collection in the mid-fourth century.
By the late fourth century it was being used to date documents throughout the Mediterranean.
In 537 CE, Roman Emperor Justinian decreed that all dates must include the indiction.Outside of Egypt, the year of the indiction generally began on 1 September (Bickerman, 1980:78).
The Anno Graecorum (A.G.) Calendar is also known as the Seleucid Era, Chaldean, or the
This calendar began at the start of the Seleucid Empire and was
assimilated into the Babylonian calendar with Macedonian month-names sometimes substituted for the Babylonian names (Stern, 2012:238). The A.G. calendar uses the same
19 year cycle of intercalations as the Babylonian calendar. There are two start dates. The Macedonian reckoning used
by court officials in the Seleucid Empire and native Greek speakers started in the Autumn of 312 BCE with the start date eventually getting fixed
to 1 Oct. 312 BCE. The Babylonian reckoning used by most Semitic speaking populations has a start date of 1 Nisan in 311 BCE. Ambraseys (2009) equates this
to 1 April, Guidoboni et al (1994) equate this with 2 April, and others equate it to 3 April. A version of the A.G. calendar was used by the Christian Syriac authors such as Pseudo-Dionysius of Tell Mahre
and Chronicon Ad Annum 1234. Syriac writing authors would have likely used the
Macedonian reckoning as this was the standard usage among these authors for the Seleucid era (Sebastian Brock, personal communication, 2021 – see also Stern, 2012:236).
In the Anno Graecorum calendar system, the day starts at sundown (Sebastian Brock, personal communication, 2022).
|Macedonian Month||Julian Equivalent||Duration (days)|
|Xanthikos||22 March - 20 April||29|
|Artemisios||21 April - 20 May||30|
|Daisios||21 May - 19 June||29|
|Panemos||20 June - 19 July||30|
|Loos||20 July - 18 Aug.||29|
|Gorpiaios||19 Aug. - 17 Sept.||30|
|Hyperberetaios||18 Sept. - 17 Oct.||29|
|Dios||18 Oct. - 16 Nov.||30|
|Apellaios||17 Nov. - 16 Dec.||29|
|Audynaios||17 Dec. - 15 Jan.||30|
|Peritios||16 Jan. 14 Febr.||29|
|Dystros||15 Febr. - 16 March||30|
|Epagomenai||17 March - 21 March||5|
The Coptic Calendar is also known as the Alexandrian Calendar. The Coptic Calendar is coordinated with the Julian Calendar and, since the 4th century CE, used a
starting year (Year 1) from 29 August 284 CE to 28 August 285 CE. A year consists of 13 months where the first 12 months have 30 days each followed an epagomenal
month which has 5 days during normal years and 6 days during leap years. This version of the Coptic calendar is frequently called the Era of Martyrs and is
frequently abbreviated as A.M. (Anno Martyrum). Coptic Leap Years are coordinated with Julian leap years however the coptic leap day is added on the last day
of the coptic year rather than on 29 February. If a Coptic year will encompass a Julian Leap year (i.e. a year where there will be a February 29),
the coptic year will start on 30 August instead of 29 August as 29 August in the previous Coptic year will be a leap day. In years such as this, the
coptic day will be a day ahead of the Julian Calendar until 29 February. Thus, for example while 21 Tuba normally corresponds to 16 January, in a Julian Leap Year
it will correspond to 17 January. The Coptic day begins at sunrise in the civil calendar and sunset in the liturgical version (Coptic Encyclopedia).
A.H. – Anno Hegirae is also known as the Muslim Calendar or the Islamic lunar calendar. The start date is the Hijra - when on Friday 16 July 622 CE, Mohammed and his followers
migrated from Mecca to Medina. The calendar consists of 12 alternating months of 30 and 29 days. Although the original calendar determined the start of each month based
on astronomical observation of the first visible crescent after a new moon, a fixed tabular calendar was developed in the 8th century CE. In the tabular calendar,
a day is added to the final (12th) month during leap years making it 30 days long instead of 29. Leap days are added every 2-3 years in a 30 year cycle which is
subject to local variation. The most common distribution is on the 2nd, 5th, 7th, 10th, 13th, 16th, 18th, 21st, 24th, 26th, and 29th year of each 30-year cycle (timeanddate.com).
The Islamic day begins at sundown.
The Hebrew Calendar is also known as the Jewish Calendar or HaLuah HaIvri (הַלּוּחַ הָעִבְרִי) in Hebrew. The Hebrew Calendar is a lunisolar calendar influenced by the Ancient
Babylonian Calendar which has undergone revisions over time. Initially, this calendar was based on sightings of the first crescent after the new moon. After the
destruction of the 2nd temple in 70 CE and throughout the diaspora, the calendar was subject to local variations. By the 4th century CE, a calendar had emerged
which was increasingly based on predicted lunar cycles. Sometime before the 8th century, a fixed 19 year Metonic cycle of intercalations similar to the Babylonian
cycle was adopted and by the early 10th century, the rabbinic calendar had become like the fixed and predictable calendar that is used today. (Stern, 2012:334-335),
The structure of the Hebrew Calendar is one of 12 months with an additional intercalary month added in years 3, 6, 8, 11, 14, 17, and 19 of the
Metonic cycle along with a complicated set of rules (Reingold and Dershowitz, 2018:Section 8.1).
The modern Hebrew Calendar is also characterized by a change in the start date of the calendar from the destruction
of the second Temple in 70 CE to the start of “creation”
like the Anno Mundi Calendar of the Byzantines.
In the Hebrew Calendar, the day begins at sundown.
4.4.1 The Present-Day Rabbinic Calendar: An Outline
Onstott (2015:386-388) notes the following:
B. The Priestly and Civil Calendars
1. Cultic Calendar
Throughout the ancient world, civilizations used two different calendar systems: a cultic calendar for religious festivities and a civil calendar for both the Crown's administration and the agricultural year. Both systems were luni-solar, which means they were based on calculable events common between both the moon and the sun.
Israel, like other ancient nations, used the solar system to begin the year and to reckon time. Israel's cultic or priestly calendar closely mirrors the calendar in Mesopotamia but is less similar to the civil calendar in Egypt (as we will see in chap. m). The year began with the spring equinox.142 The first day of the new year began on the first day of the first full month (or new moon) after the equinox, placing the new year between the end of March and the first part of May.143
The Hebrew Scriptures only mention four of the months in Israel's original cultic calendar: Aviv, Ziv, Ethanim, and Bul.144 Aviv was the first month of the year, Ziv the second, Ethanim the seventh, and Bul the eighth.145 These names are quite similar to Canaanite names, from which we infer that Israel and Canaan may have shared the same yearly calendrical system since the seasons were the same for Canaanite territory.146 By the time Ezra worked to update and codify Israel's various manuscripts, the names of Canaan's months had virtually been replaced by Babylonian names. As Andrew Steinmann observes, "During the Babylonian exile the Judeans apparently substituted the Babylonian names for the months into Hebrew. These names are occasionally used in the postexilic books of the Tanakh and are common in later Hebrew" (see Table 9.23).147Table 9.23
2. Civil Calendar
Before the Monarchy, Israel had relied solely on the cultic or priestly calendar established in the Torah. Since only one calendar was in play, it produced the straightforward linear chronology used during the Judges' Era. All this changed under the Monarchy, when Israel asked for a king, the people wanted a government similar to other nations (Deut 7:14; 1 Sam 8:20). One practice of ancient monarchies was to employ a second, "fiscal" or civil year.148 Many synchronisms in Scripture indicate that after Samuel instituted the Monarchy, the nation transitioned to a civil calendar, similar to the civil calendars prevalent in Egypt and Mesopotamia.149 While the priestly-cultic calendar began the new year in the spring with the vernal equinox,150 the Monarchy's civil-agricultural calendar began with the autumnal equinox in the fall in the 7th month of Ethanim (i Kgs 8:2), better known as Tishri.151 The famed loth century calendar excavated at Gezer is an example of the Tishri-based agricul-tural/civil calendar.152 This does not mean that the priestly calendar was abandoned but that a second, administrative system was in use by the end of King Solomon's reign.Footnotes
142. Wagenaar, Israelite Festival Calendar, 30-44, 62-78; Steinmann, Abraham to Paul, 15-30; Miano, Shadow Steps, 31-32; Steinmann, Abraham to Paul, 12-30; Finegan, Handbook, 16-17, 25-31; Leo Depuydt, Civil Calendar and Lunar Calendar in Ancient Egypt (Belgium: Peeters, 1997) 15-20, 23, 43, 50-56, 61-63.
143. Finegan, Handbook, 29-33.
144. Aviv—Exod 13:4, 23:15; 34:18; Deut 16:1; Ziv-1 Kgs 6:1, 37; Ethanim—Judg 8:2; and Bul-1 Kgs 6:38. See also Steinmann, Abraham to Paul, 12-16.
145. Finegan, Handbook, 30-33 and Steinmann, Abraham to Paul, 13-16.
146. Steinmann, Abraham to Paul, 15. Nisan—Neh 2:1; Esth 3:7. Sivan—Esth 8:9. Kislev— Neh 1:1. Tebeth—Esth 2:16. Shebat—Zech 1:7. Adar—Ezra 6:15; Esth 3:7,13; 8:12; 9:1, 15, 17, 19.
147. Finegan, Handbook, 21-22, 21, 33; Steinmann, Abraham to Paul, 17-21; Thiele, Mysterious Numbers, 44-50; and Wagenaar, Origin and Transformation, 13-24.
148. Finegan, Handbook, 21, 33-35; Steinmann, Abraham to Paul, 17-21; and Thiele, Mysterious Numbers, 44-50.
149. Finegan, Handbook, 21-22, 21, 33; Steinmann, Abraham to Paul, 17-21; Thiele, Mysterious Numbers, 44-50; and Wagenaar, Origin and Transformation, 13-24.
150. Wagenaar, Origin and Transformation, 13-14; and Finegan, Handbook, 29-31.
151. Finegan, Handbook, 21.
152. Wagenaar, Origin and Transformation, 14-17.
Longman, T., Dillard, R.B. (1994). An Introduction to the Old Testament, Zondervan.
Onstott, J. (2015). YHWH Exists, Vol. 1: Placing God on Trial: an In depth Look at the Validity and Historicity of the Hebrew Scriptures, Emmanuel Academic Publishing, Incorporated. Excerpts on Micro and Macro Chronology
Schoors, Antoon. The Kingdoms of Israel and Judah in the Eighth and Seventh Centuries B.C.E.. United States, SBL Press, 2013.
Thiele, E. R. (1983). The Mysterious Numbers of the Hebrew Kings, Academic Books. - bookmarked to the start of Chapter 6 - The Chronology of Judah and Israel (841-723 BC) - can be borrowed with a free archive.org account
The Mysterious Numbers of the Hebrew Kings - Thiele's chronology (wikipedia)
The Bostran era (also called the era of Bostra, the Arabian era or provincial era) was a calendar era
(year numbering) with an epoch (start date) corresponding to 22 March 106 AD. It was the official era of
the Roman province of Arabia Petraea, introduced to replace dating by regnal years after the Roman
annexation of the Nabataean Kingdom. It is named after the city of Bostra, which became the
headquarters of the Sixth Legion stationed in the province.