A short course in courses

All

KJV: Also for the courses of the priests and the Levites, and for all the work of the service of the house of the LORD, and for all the vessels of service in the house of the LORD.

Hebrew: ולמחלקות הכהנים והלוים ולכל מלאכת עבודת בית יהוה ולכל כלי עבודת בית יהוה׃

Greek: και των καταλυματων των εφημεριων των ιερεων και των λευιτων εις πασαν εργασιαν λειτουργιας οικου κυριου και των αποθηκων των λειτουργησιμων σκευων της λατρειας οικου κυριου

Latin: divisionumque sacerdotalium et leviticarum in omnia opera domus Domini et in universa vasa ministerii templi Domini

Wycliffe: and of the departyngis of preestis and of dekenes, in to alle the werkis of the hows of the Lord, and alle vessels of the seruyce of the temple of the Lord.

The following verses from 1 Chronicles detail the courses. The sequence of numbers in interesting but not covered further here.

1 Chronicles 24:3

All

KJV: And David distributed them, both Zadok of the sons of Eleazar, and Ahimelech of the sons of Ithamar, according to their offices in their service.

Hebrew: ויחלקם דויד וצדוק מן בני אלעזר ואחימלך מן בני איתמר לפקדתם בעבדתם׃

Greek: και διειλεν αυτους δαυιδ και σαδωκ εκ των υιων ελεαζαρ και αχιμελεχ εκ των υιων ιθαμαρ κατα την επισκεψιν αυτων κατα την λειτουργιαν αυτων κατ οικους πατριων αυτων

1 Chronicles 24:4

All

KJV: And there were more chief men found of the sons of Eleazar than of the sons of Ithamar; and thus were they divided. Among the sons of Eleazar there were sixteen chief men of the house of their fathers, and eight among the sons of Ithamar according to the house of their fathers.

Hebrew: וימצאו בני אלעזר רבים לראשי הגברים מן בני איתמר ויחלקום לבני אלעזר ראשים לבית אבות ששה עשר ולבני איתמר לבית אבותם שמונה׃

Greek: και ευρεθησαν υιοι ελεαζαρ πλειους εις αρχοντας των δυνατων παρα τους υιους ιθαμαρ και διειλεν αυτους τοις υιοις ελεαζαρ αρχοντας εις οικους πατριων εξ και δεκα και τοις υιοις ιθαμαρ οκτω κατ οικους πατριων

The courses were divided by lot.

1 Chronicles 24:5

All

KJV: Thus were they divided by lot, one sort with another; for the governors of the sanctuary, and governors of the house of God, were of the sons of Eleazar, and of the sons of Ithamar.

Hebrew: ויחלקום בגורלות אלה עם אלה כי היו שרי קדש ושרי האלהים מבני אלעזר ובבני איתמר׃

Greek: και διειλεν αυτους κατα κληρους τουτους προς τουτους οτι ησαν αρχοντες των αγιων και αρχοντες κυριου εν τοις υιοις ελεαζαρ και εν τοις υιοις ιθαμαρ

1 Chronicles 24:7

All

KJV: Now the first lot came forth to Jehoiarib, the second to Jedaiah,

Hebrew: ויצא הגורל הראשון ליהויריב לידעיה השני׃

Greek: και εξηλθεν ο κληρος ο πρωτος τω ιαριβ τω ιδεια ο δευτερος

1 Chronicles 24:8

All

KJV: The third to Harim, the fourth to Seorim,

Hebrew: לחרם השלישי לשערים הרבעי׃

Greek: τω χαρημ ο τριτος τω σεωριμ ο τεταρτος

1 Chronicles 24:9

All

KJV: The fifth to Malchijah, the sixth to Mijamin,

Hebrew: למלכיה החמישי למימן הששי׃

Greek: τω μελχια ο πεμπτος τω μιαμιν ο εκτος

We will be interested in the eighth course, that of Abijah, to which Zechariah, father of John the Baptist, belonged.

1 Chronicles 24:10

All

KJV: The seventh to Hakkoz, the eighth to Abijah,

Hebrew: להקוץ השבעי לאביה השמיני׃

Greek: τω κως ο εβδομος τω αβια ο ογδοος

1 Chronicles 24:11

All

KJV: The ninth to Jeshua, the tenth to Shecaniah,

Hebrew: לישוע התשעי לשכניהו העשרי׃

Greek: τω ιησου ο ενατος τω σεχενια ο δεκατος

1 Chronicles 24:12

All

KJV: The eleventh to Eliashib, the twelfth to Jakim,

Hebrew: לאלישיב עשתי עשר ליקים שנים עשר׃

Greek: τω ελιασιβ ο ενδεκατος τω ιακιμ ο δωδεκατος

1 Chronicles 24:13

All

KJV: The thirteenth to Huppah, the fourteenth to Jeshebeab,

Hebrew: לחפה שלשה עשר לישבאב ארבעה עשר׃

Greek: τω οχχοφφα ο τρισκαιδεκατος τω ισβααλ ο τεσσαρεσκαιδεκατος

1 Chronicles 24:14

All

KJV: The fifteenth to Bilgah, the sixteenth to Immer,

Hebrew: לבלגה חמשה עשר לאמר ששה עשר׃

Greek: τω βελγα ο πεντεκαιδεκατος τω εμμηρ ο εκκαιδεκατος

1 Chronicles 24:15

All

KJV: The seventeenth to Hezir, the eighteenth to Aphses,

Hebrew: לחזיר שבעה עשר להפצץ שמונה עשר׃

Greek: τω χηζιρ ο επτακαιδεκατος τω αφεσση ο οκτωκαιδεκατος

1 Chronicles 24:16

All

KJV: The nineteenth to Pethahiah, the twentieth to Jehezekel,

Hebrew: לפתחיה תשעה עשר ליחזקאל העשרים׃

Greek: τω φεταια ο εννεακαιδεκατος τω εζεκηλ ο εικοστος

1 Chronicles 24:17

All

KJV: The one and twentieth to Jachin, the two and twentieth to Gamul,

Hebrew: ליכין אחד ועשרים לגמול שנים ועשרים׃

Greek: τω ιαχιν ο εις και εικοστος τω γαμουλ ο δευτερος και εικοστος

1 Chronicles 24:18

All

KJV: The three and twentieth to Delaiah, the four and twentieth to Maaziah.

Hebrew: לדליהו שלשה ועשרים למעזיהו ארבעה ועשרים׃

Greek: τω δαλαια ο τριτος και εικοστος τω μαασαι ο τεταρτος και εικοστος

Priestly courses
First	Jehoiarib
Second	Jedaiah
Third	Harim
Fourth	Seorim
Fifth	Malchijah
Sixth	Mijamin
Seventh	Hakkoz
Eighth	Abijah	Zacharia
Ninth	Jeshua
Tenth	Shecaniah
Eleventh	Eliashib
Twelfth	Jakim
Thirteenth	Huppah
Fourteenth	Jeshebeab
Fifteenth	Bilgah
Sixteenth	Immer
Seventeenth	Hezir
Eighteenth	Happizzez
Nineteenth	Pethahiah
Twentieth	Jehezkel
Twenty‑first	Jachin
Twenty‑second	Gamul
Twenty‑third	Delaiah
Twenty‑fourth	Maaziah

To what course did Zacharias belong?

Luke 1:5 There was in the days of Herod, the king of Judaea, a certain priest named Zacharias, of the course of Abia: and his wife was of the daughters of Aaron, and her name was Elisabeth. [kjv]

εγενετο εν ταις ημεραις ηρωδου βασιλεως της ιουδαιας ιερευς τις ονοματι ζαχαριας εξ εφημεριας αβια και γυνη αυτω εκ των θυγατερων ααρων και το ονομα αυτης ελισαβετ [gnt]

The course of Abijah was the 8th of 24 courses.

Luke 1:5

All

KJV: There was in the days of Herod, the king of Judaea, a certain priest named Zacharias, of the course of Abia: and his wife was of the daughters of Aaron, and her name was Elisabeth.

Greek: εγενετο εν ταις ημεραις ηρωδου του βασιλεως της ιουδαιας ιερευς τις ονοματι ζαχαριας εξ εφημεριας αβια και η γυνη αυτου αυτω εκ των θυγατερων ααρων και το ονομα αυτης ελισαβετ

Each course served 1 week or 7 days (with one day overlap).

Josephus records the last course serving before the Temple was destroyed on August 5, 70 A.D.

How many weeks in a year? (52 plus 1 or 2 days)

How many extra days each year? ((52-48)*7+1 or 29 days, about 4 courses).

One can backtrack using when Zacharias ended his duties, then add 280 days for the birth of Jesus.

It appears it would have been in Spring (Passover) or Fall (perhaps Trumpets).

Picking Feast of Trumpets in late September to announce the birth (guest rooms would have been full, needed to meet census requirements) means the immaculate conception of Jesus would have been about December 25.