This webpage is part of the website www.janzuidhoek.net which promotes the new book on early Alexandrian Paschal reckoning [Jan Zuidhoek (2021) Reconstructing Metonic 19-year Lunar Cycles (on the basis of NASA’s Six Millennium Catalog of Phases of the Moon): Zwolle] and concerns five important Alexandrian Metonic lunar cycles dealt with in this groundbreaking book, which is available via this website.

 

 

 

Five Alexandrian Metonic lunar Cycles                                        

 

Five Alexandrian Metonic Lunar Cycles

 

Anatolius’ lunar cycle

archet. Alex. lunar cycle

Festal Index lunar cycle 

Theophilus’ lunar cycle

class. Alex. lunar cycle

AD

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

8 April

28 March

16 April

5 April

24 March

12 April

1 April

20 April

9 April

29 March

17 April

6 April

26 March

14 April

3 April

23 March

11 April

31 March

19 April

6 April

26 March

13 April

2 April

22 March

10 April

30 March

18 April

7 April

27 March

15 April

4 April

24 March

12 April

1 April

21 March

9 April

29 March

17 April

6 April

26 March

14 April

2 April

22 March

10 April

30 March

18 April

7 April

27 March

15 April

4 April

24 March

12 April

1 April

21 March

9 April

29 March

17 April

6 April

26 March

13 April

2 April

22 March

10 April

30 March

18 April

7 April

27 March

15 April

4 April

24 March

12 April

1 April

21 March

9 April

29 March

17 April

5 April

25 March

13 April

2 April

22 March

10 april

30 March

18 April

7 April

27 March

15 April

4 April

24 March

12 April

1 April

21 March

9 April

29 March

17 April

Table 8: Comparing two lost ante-Nicene and the three well‑known post‑Nicene Alexandrian Metonic (19‑year) lunar cycles to each other

 

The Festal Index (19‑year) lunar cycle, Theophilus’ (19‑year) lunar cycle, and the classical Alexandrian (19‑year) lunar cycle are known as the three well‑known post‑Nicene Alexandrian Metonic lunar cycles. They date from after the first council of Nicaea (AD 325). Much less known are Anatolius’ (19‑year) lunar cycle and the archetypal Alexandrian (19‑year) lunar cycle, which date from before the first council of Nicaea.

Anatolius’ lunar cycle is the (lost) Metonic lunar cycle from which the great Alexandrian computist Anatolius, who was bishop of Laodicea (Syria) from AD 268 to his death in about AD 282, ultimately started to construct his legendary (19‑year) Paschal cycle; the archetypal Alexandrian lunar cycle is the (also lost) Metonic lunar cycle which is just the common archetype of the three well‑known post‑Nicene Alexandrian Metonic lunar cycles, but was constructed shortly before the first council of Nicaea. Both these ante‑Nicene Metonic lunar cycles were constructed (before AD 325) and reconstructed (recently) mutatis mutandis according to four computistical principles: the principle concerning the spring equinox, the principle concerning the crescent moon, the principle of periodicity, and the principle of metonicity.

The Festal Index lunar cycle is the improvised Metonic lunar cycle used by the very first compiler of the Festal Letters of bishop Athanasius of Alexandria; this Metonic lunar cycle can be considered to have been obtained from the archetypal Alexandrian lunar cycle by simply replacing its date 13 April with 14 April. Theophilus’ lunar cycle, being the Metonic lunar cycle introduced by bishop Theophilus of Alexandria in order to structure his Paschal table of 100 years, can be considered to have been obtained by simply adopting the archetypal Alexandrian lunar cycle or by adapting the Festal Index lunar cycle by simply replacing its date 14 April with 13 April. The classical Alexandrian lunar cycle is Annianus’ lunar cycle, being the Metonic lunar cycle opted for by the Alexandrian monk and great computist Annianus (in about AD 412) and sooner or later adopted by the episcopacy of the church of Alexandria. It is this particular Metonic lunar cycle which forms the Metonic structure underlying both Dionysius Exiguus’ Paschal table (of 95 years), composed in about AD 525, and Beda Venerabilis’ Easter table (of 532 years), composed relatively shortly before or in AD 725.

We observe that there exists a gap of about 2 days between Anatolius’ lunar cycle on the one hand and both the archetypal Alexandrian lunar cycle and the three well‑known post‑Nicene Alexandrian Metonic lunar cycles on the other. Clearly this 2‑day gap dates from before the first council of Nicaea in AD 325, and is therefore referred to as the ante‑Nicene Alexandrian 2‑day gap.

 

 

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© Jan Zuidhoek 2019-2023

(updated 13‑2‑2023)