other socialauthorities are never called upon, therefore, to determine it or set
it. This calendar is consequently universal, democratic, and accessibletoall;
but the corollary is that calendar reckoning in modern times haslargely ceased
to belong to the politicaldomain.^3
This is not to say, however, thatfixed calendars—by whichImean, calen-
dars determined in advance by a set calculation or following a set scheme—are
a purely modern phenomenon. They existedlong before the institution of the
Gregorian calendar in the sixteenth century. Already inlate Antiquity, by the
third centuryCE,fixed calendars pervaded the Mediterranean and the Near
East. The western half of the Roman Empire was dominated by the Julian
calendar, precursor of our Gregorian calendar; whilst the cities and provinces
of the Roman East almost allmodelled their calendars, in various ways, on the
Julian calendar, with afixed sequence of twelve months, a 365-day year, and
an extra day every four years. Further east, in thePersian Empire, Sasanian
rulers were also using afixed calendar, consisting more simply of a twelve-
month, 365-day year (withoutleap years).
The situation had been quite different a thousand years earlier. Around 500
BCE, the numerous calendars of Greece, Asia Minor, and the Near East were
nearlyallflexible, determined on a month-to-month basis, and under the
controland whim of politicalrulers. The only exception was the calendar of
Egypt, which from ancient times had always beenfixed; as we shallsee, it is
largely out of this singlecalendar, directly or indirectly, thatfixed calendars
spread to the rest of the Roman andPersian Empires by thelate antique
period.
The explanation of how and why ancient calendars developed along this
apparently common trajectory, fromflexibility in the mid-first millenniumBCE
tofixed schemes inlate Antiquity, willbe one of the main challenges of this
present study. This trajectory has often been explained as an outcome of
civilization or progress—an explanation that is unconvincing for a number
of reasons. As we shallsee,flexiblecalendars were retained by some of the
most scientifically advanced societies in Antiquity, for reasons that are easy to
understand: politicalrulers who used flexiblecalendars as a means of
controlling society had every politicalinterest to maintain the status quo.
The adoption of afixed calendar invariably meant the abdication, by political
rulers, of an important source of politicalprestige and socialcontrol. From this
politicalperspective, the question should not so much be why the rulers of
some ancient societies maintained theirflexiblecalendars, but rather, on the
(^3) Iam referring specificallytocalendar reckoning or the structure of the calendar, rather than
to the contents of the calendar, e.g. the dates of public holidays, with which modern governments
frequently interfere (the distinction between calendar structure and contents willbe explained
further below). On the extent to which the calendar has remained part of the politicaldomain in
the modern world, if only at thelevelof politicaldebate and reform proposals, see Rüpke (2006).
Introduction 3