The term Hemerologia identifies a set of comparative calendar tables preserved in early Medieval Greek manuscripts listing in parallel columns the days of the month according to the Roman (Julian) calendar, which serves as common reference point, and a number of local calendars of the provinces and cities of the eastern half of the Roman Empire. Thus, the Hemerologia not only provide abundant information on the diversity of calendars of the provinces and cities of the Roman East, but also on their assimilation in the Roman period to a fixed and stable common denominator, the 365-day year of the Julian calendar.
Soon after its introduction in 46 BCE, the Julian calendar started spreading throughout the Empire, although its diffusion differed considerably between the western and the eastern provinces: whereas it appears that in the West the new calendar spread massively and soon completely replaced all local calendars, in the eastern provinces –especially in Asia Minor, Egypt, and the Near East– it also spread quickly but did not supplant pre-existing calendars.
Different Hemerologia tables are known in four manuscripts:
- Leidensis BPG 78 copied in the early ninth century
- Vaticanus gr. 1291 copied in the early ninth century
- Laurentianus 28/26 attributed to the late ninth or early tenth century
- Laurentianus 28/12 is a fourteenth century copy of the Leiden manuscript
These manuscripts were edited in 1915 by Wilhelm Kubitschek, who also compared the data of their Hemerologia to the evidence of literary and epigraphic sources.
Although the four manuscripts that preserve the Hemerologia were produced in medieval times, it is clear that the tables themselves originated during the Roman Imperial period or in late antiquity, when the calendars that appear in the tables were still in use. Indeed, similar calendrical equivalences appear in literary, documentary, and epigraphic sources dating from the early imperial period to late antiquity.
Our research in this area consists in a re-assessment of the information provided by these manuscripts by taking into account newly discovered epigraphic and documentary evidence since Kubitschek’s work over a century ago. Some of our main findings can be summarised as follows:
- Inconsistencies amongst Hemerologia manuscripts and with external evidence may occasionally have arisen as a result of scribal error, but it is plausible to assume that in some cases they reflect regional diversity of calendars and/or diachronic change.
- It appears that in the Middle Ages the Hemerologia were consistently transmitted along with Ptolemy’s Handy Tables. This fact is certainly significant but does not necessarily imply that the tables were originally produced as part of a scholarly, scientific tradition during the Roman imperial period or in late antiquity. It seems more likely that they were created for one or more different purposes and were subsequently ‘reused’ to assist medieval astronomers and astrologers in their calculations.
- In addition to fulfilling various practical uses, the Hemerologia carried ideological and political significance, representing local adherence to the Roman Imperial power. The Hemerologia could also be seen as an instrument for the fixation of provincial calendars, the imposition of conformity to the Julian calendar, and thus as a signal of Roman hegemony in the East.
- The Hemerologia thus illustrate the complexity of the social and political dynamics associated to the Roman presence in the East and to the relationship between the Romans and their subjects in those areas. Moreover, the fact that the Julian calendar did not spread in the same way in the Western and in the Eastern provinces of the Empire reflects the social, political, and cultural variety that characterised the different areas of the Roman Empire.