Anno Mundi, dating systems of Orthodox Christians and Jews, means "year of the world," and begins when the very widely disputed biblical year of creation occurred. It was much earlier for early Christians and Jews that use the Septuagint than Bishop Ussher’s 17th c. calculation that is, I believe, identical to the current Jewish Masoretic calculation, of October 7 3,761
Septuagint date for creation that the Byzantine Empire used after revising the
still-relevant Chronicon Paschale is 31
Aug to 1 Sept 5508 BCE (the
Chronicon Pascale began March 21 5507 BCE,
which itself replaced the Alexandrian Calendar, which began March 25, 5493 BCE). The Byzantine and later Roman year, including
the indictional (fiscal) sequence of Justinian, began Sept. 1, not January 1 (as
in the Julian calendar and later Gregorian Calendar that we use today), or the
Sidereal-lunar calendars that began on either March 21 or 25th.
The Chronicon Paschale was the basis of the computuus used to calculate the movable feasts using lunar cycles, and incorporates a fixed date representing an the Spring equinox; in actuality, the equinox was calculated uniquely for each year, as the equinox was recognized to drift. September 1 was the usual fiscal year practiced during the medieval period in England and in most of the European and Mediterranean world - anybody who had been influenced by at least the Alexandrian period of Roman rule, which originally was a five year period beginning in Roman Alexandria 287 CE, as a cycle of land and agricultural tax reassessment, establishes its initial year as 297/8 CE according to a Coptic document dating to 933 CE , and became a 15 year period by 314 CE, with the ca. 633 CE Chronicon Paschale establishing an initial date of September 312/313 CE, since Constantine had triumphed during the Battle of the Milvian Bridge, defeating the usurper Maxentius, after having ordered his troops to inscribe 'in hoc signo vinces' and the XP monogram (chi-rho: the Christogram) on their standards and shields.
297 CE was the year of completion of Diocletian's sweeping empire-wide fiscal reform, following the monetary reform that began in 293, with mint reforms occurring until 296, when the Greek-derived drachm system was replaced by the Pan-Roman currency system, as were all provincial currency systems. Local civic mints were closed and large-scale regional mints were then opened and their monetary production exponentially increased to re-supply the provinces with their small change. Census were ordered to be conducted on a 5-15 year bases as well, and I assume that these were most likely to occur directly preceding the indictional revisions, where one indiction was equivalent half of the period of average life expectancy. For the purview of government, all calendar and period-cycle codification revolved around taxation and optimal strategies to control inflation and influx of foreign currency, and to control military allegiance with proper allotment of currency in order to protect farmland and infrastructure. Tax adjustment and the census were concomitant, since growth and costs changed only semi-covariantly, although these were correlated. Force was used to impose fiat cultural and social values, which included the circulation of currency, bearing the emblems and current messages from the state.
Rome had elevated money (its common thread, as no central religion dominated) to the status of a sacred fetish, Sacra Moneta, and who was personified by the abstract feminine deity Moneta. The name Moneta also referred to the derived cognate form of Mnemosyne, the Greek goddess of memory (and mother of the Muses) – and from the Latin word monere, which means “to remind, warn, or instruct” http://en.wikipedia.org/wiki/Moneta. More appropriately though, Juno Moneta engendered Sacra Moneta: she was the figurative mother of figurative money – and the term moneta then etymologically descended by way of the Greek word μονήρης, (‘moneres,’ meaning “unique, alone”); Juno Moneta was the protector of finances, whose temples WERE the mints, and as such sacrosanct places as well. The implication is that money was the unique memory of the State, as well as the mother of arts, literature, sciences, and to all forms of creative and constructive exploits – a “reminder,” and “alone” among all other media and things. Money was already functioning as proto-archaeological/proto-paleographical evidence.
Coin collecting, probably as a component of a collection of art and documents required as references for international political functionality was also practiced by Augustus, and I assume that this was pragmatic, as the coinage of Greek predecessors often had dates, and these Ptolemaic and Seleucid coins had become objects for collection, and were likely seen as tokens of cultural expansion that could be interpreted by Romans to suffice for evidence of legitimate control over a region linked this way to precursory Greek kingdoms that had become controlled by Rome. Money alone survives in the sediments, when no other chronology can be constructed, as structures and texts are destroyed easily and commonly. When the decision to debase coinage was made, reference specimens from competitive foreign currency systems must have been accumulated in order to avoid triggering economic panic beginning in ports.
The initials for Sacra Moneta were frequently inscribed on coinage in abbreviated form well into the reference to Sacra Moneta survived into the Christian era, as SM, part of the exergual legend on the reverse side of a coin that included the mintmark and the letter indicating the officina, or specific department of the mint in which it was made). Moneta, as an effigy, was often featured on the reverse side of a coin, such as this coin of Diocletian from Alexandria, a tetradrachm dating from year two, or 285/6 CE, before the rather lagged final issue of the post-Ptolemaic standard coinage of 297/7 CE, which would have been reignal year 13. http://www.vcoins.com/es/stores/shick_coins/202/product/egypt_alexandria_diocletian_284305_ad_moneta_standing/441880/Default.aspx; and here is a follis, from after the monetary reform, of Aquileia, with Moneta http://wildwinds.com/coins/ric/diocletian/_aquileia_RIC_029a.jpg. Here is another coin of Diocletian struck in Alexandria after the reform, showing the new
ALE mintmark: http://www.coinproject.com/siteimages/101-1950287.jpg
Interestingly, this posthumous coin http://wildwinds.com/coins/ric/constantine/_alexandria_RIC_viii_012.jpg commemorates the deification of Constantine – and AFTER his official conversion to Christianity, by his Christian son Constantine II, in 337-340 CE (although before Christianity became the official imperial religion), an example of one of the four types, having the veiled head of the emperor Constantine I on its obverse, and the emperor riding in a fast quadriga with the very Christian motif of a hand of God reaching for him, was also struck in Alexandria (and also at many other mints), and has the mintmark of SMAL_A.