Dates on Roman Provincial Coins

During Hellenistic times, the practice of placing dates on coins became common, particularly in the eastern part of the Greek world. Dates are either based on a known era, for example the Seleukid era, or based on a regnal year. Many era dates are used, but the most common era dates found on Roman Provincial coins are Seleukid (year 1 being 312 BC when Seleukos took possession of Babylon), Actian (year 1 being the defeat of Antony by Octavian at Actium in 31 BC), Pompeian (year 1 being 64 BC) and Caesarean (year 1 being 49 BC, though sometimes 48 or 47 BC). Foundation dates are also popular, year 1 being the year in which a city was founded. Regnal dates are for the most part limited to Egypt and the long series of Alexandrian coins. Dates on provincial coins are usually  expressed with Greek letters with each letter representing number. The table below shows the correlations:

 

1 - A 9 - Q 80 - P
2 - B 10 - I 90 - Q
3 - G 20 - K 100 - P
4 - D 30 - L 200 - S or C
5 - E or e 40 - M 300 - T
6 - S or x 50 - N 400 - Y
7 - Z 60 - X 500 - F
8 - H 70 - O 600 - X

 

One of the confusing issues regarding dates is they can read from either right to left or left to right. So year 528 can be either FKH or HKF. Here are a few other examples: 216 = SIS, 374 = TOD, 188 = PPH.

Dates are sometimes preceded by the word ETOYS (which means "year") which can also be abbreviated ET or just E.

In Alexandria, as previously stated, dates are given in regnal years and the word ETOYS is usually replaced with the letter L. Thus for Year 15 of Hadrian's reign you would have the date reading L IE which would be equivalent to 130/131 AD. Also in Alexandria the regnal year number is sometimes written in full:: TPITOY (3), TETAPTOY (4), ENATOY (9), DEKATOY (10), ENDEKATOY (11), DwDEKATOY (12), TRICKAIDEKA (13), and ENNEAKD (19).

More to follow.

Source: Greek Imperial Coins and Their Values, by David Sear.