The Ancient Greek Calendar

The Hellenic calendar—or more properly, the Hellenic calendars, for there was no uniform calendar imposed upon all of Classical Greece—began in most Greek states between Autumn and Winter except the Attic calendar, which began in Summer. The Greeks, as early as the time of Homer, appear to have been perfectly familiar with the division of the year into the twelve lunar months but no intercalary month Embolimos or day is then mentioned. Independent of the division of a month into days, it was divided into periods according to the increase and decrease of the moon. Thus, the first day or new moon was called Noumenia. The month in which the year began, as well as the names of the months, differed among the states, and in some parts even no names existed for the months, as they were distinguished only numerically, as the first, second, third, fourth month, etc.

Attic Calendar

The Attic calendar is the calendar that was in use in ancient Attica, the ancestral territory of the Athenian polis. This article focuses on the 5th and 4th centuries BC, the classical period that produced some of the most significant works of ancient Greek literature. Because of the relative wealth of evidence from Athens it is the best understood of all the Hellenic calendars. Viewed from the standpoint of the modern Gregorian calendar, this ancient system has many peculiar features. This is a part of its appeal: as a cultural artifact, it opens a window to the mentality of its users.

Although relatively abundant, the evidence for the Attic calendar is still patchy and often of contested interpretation. As it was obvious to ancient Athenians, no contemporary source set out to describe the system as a whole. Further, during the period in question the calendar underwent changes, not all perfectly understood. As such, any account given of it can only be a tentative reconstruction. Note that in this context the terms Athenian and Attic are largely interchangeable.

Local focus of the system

The Attic calendar was an exclusively local phenomenon, used to regulate the internal affairs of the Athenians and with little relevance to the outside world. For example, just across the border in Boeotia not only did the months have different names, but the year began in mid-winter. In Athens the year began six months later, just after mid-summer. Furthermore, while Greek months were supposed to begin with the first sighting of the new moon, this was determined locally and with a degree of variability. In many years the months in the two communities would have more or less coincided, but there is no sign that they tried to keep the days of the month exactly aligned: they would have seen no reason to do so.

The divide between these neighbouring calendars perhaps reflected the traditional hostility between the two communities. Had the Boeotians been speakers of an Ionic dialect, like that spoken in Athens, there would have been overlap in the names of months. An example of this is the Ionian island of Delos, where the calendar shared four out of twelve month names with Athens, but not in the same places in the year. There, even though the island was under some degree of Athenian control from around 479 to 314 BC, the year started, as with the Boeotians, at midwinter.

More than one calendar

Athenians lived in fact under a number of simultaneous calendars, used to fix days for different purposes. How much each calendar meant to an individual must have depended on how they lived. They may be set out as follows:

Festival calendar - List of months

No complete list survives anywhere with all twelve months set out in order, but the following reconstruction is certain. Note also that the correlation suggested here between the Athenian months and those of the modern (Gregorian) calendar is only loose, and, in some years, might have been out by over a month.

Summer (Θέρος)

1 Hekatombaion (Ἑκατομβαιών) July/August
2 Metageitnion (Μεταγειτνιών) August/September
3 Boedromion (Βοηδρομιών) September/October

Autumn (Φθινόπωρον)

4 Pyanepsion (Πυανεψιών) October/November
5 Maimakterion (Μαιμακτηριών) November/December
6 Poseideon (Ποσειδεών) December/January

Winter (Χεῖμα)

7 Gamelion (Γαμηλιών) January/February
8 Anthesterion (Ἀνθεστηριών) February/March
9 Elaphebolion (Ἑλαφηβολιών) March/April

Spring (Ἔαρ)

10 Mounichion (Μουνιχιών) April/May
11 Thargelion (Θαργηλιών) May/June
12 Skirophorion (Σκιροφοριών) June/July

Lunisolar calendar

The year was meant to begin with the first sighting of the new moon after the summer solstice. The solstice is when the rising and setting points of the sun on the horizon, which have been creeping north over the past half-year, appear to remain in the same place for a few days before beginning their drift back toward the south. Ideally, the solstice was to occur in the last month of the year. Then, on the day after the evening when the first sliver of the new moon had been seen (or presumed to have been seen), the new year was to begin. Because the relation of these two events, solstice and new moon, is variable, the new year would have moved (in relation to a Gregorian date) by up to a month.

The linking of the sun and the moon meant that the calendar was lunisolar. Twelve lunar months add up to about 354 days, eleven days or so shorter than the solar year. Under a purely lunar calendar, such as the Islamic one, the months creep backwards over the years with no relation between the months and the seasons. In Greece with its pronounced seasons this had to be prevented. By tying the start of their year to the solstice, the Athenians allowed the months to relate, with some elasticity, to the seasons.

This still left the problem that twelve lunar months fall eleven days short of the solar year. To make up for this, an extra month had to be inserted ("intercalated") about every third year, leading to a leap year of about 384 days. So normal years contained 12 lunar cycles and then when it was judged that the months had slid back enough, a year of 13 cycles was used to realign the lunar and solar years. This extra month was achieved by repeating an existing month. That is to say, the same month name was used twice in a row. Handbooks usually refer to the sixth month, Poseideon, as the month that was repeated, but months 1, 2, 6, 7 and 8 are all attested as being doubled. (Hannah 2005: 43)

Various cycles were in existence for working out exactly which years needed to take a thirteen month. A nineteen-year cycle known as the Metonic cycle which was developed at Athens by the astronomers Meton and Euctemon (known to be active in 432 BC), could have been used to pattern the insertion of leap years so as to keep the lunar and solar years aligned with some accuracy. There is, however, no sign that any such system was in fact used at Athens, where the calendar seems to have been administered on an ad hoc basis.

Names of the months

The first function of this calendar was to set the days for the religious festivals. These festivals, in a county fair role, encompassed a much broader range of activities than the word "religious" suggests, and were central to the life of the city.

The Athenian months were named after gods and festivals. In this the calendar differed from the Mesopotamian models that lie behind all Greek lunar calendars. In the Sumerian and Babylonian prototypes, for instance, the months were named after the main agricultural activity practised in that month. Many Athenian festivals did have links with different stages of the agricultural cycle, such as festivals of planting or harvest. This perhaps added to the need to keep lunar and solar calendars roughly aligned, though this was not always achieved. The year of farmers, however, was not the primary focus of the calendar.

Athenian festivals were divided between the 80 or so annually recurring celebrations and a set of monthly holy days clustered around the beginning of each month. These were often the birthdays of gods, the Greeks thinking of birthdays as a monthly rather than a yearly recurrence. Every month days 1-4 and 6-8 were all sacred to particular gods or divine entities, amounting to some 60 days a year:

Day 1: New Moon
Day 2: Agathos Daimon
Day 3: Athena's Birthday
Day 4: Heracles, Hermes, Aphrodite and Eros
Day 6: Artemis' Birthday
Day 7: Apollo's Birthday
Day 8: Poseidon and Theseus (Mikalson 1975: 24)

Monthly and annual festivals were not usually allowed to fall on the same days. This means that every festival month had an opening phase with exactly recurrent practices and celebrations, while in the body of each month there was a unique schedule of festival days.

A parallel function of this calendar was the positioning of the perhaps 15 or so forbidden days on which business should not be transacted. This practice is not still currently in use.

Sidereal calendar

A third calendar regulating Athenian lives was solar or seasonal. As such, it was fundamental for seasonal activities like farming and sailing. Within the broad divisions of the seasons, it relied on star risings and settings to mark more precise points in time. Star risings are the days when particular stars or constellations that have been below the horizon during hours of darkness first appear after sunset. Different star risings were keyed to various farm tasks, such as when to harvest: Hesiod in the Works and Days urges the farmer to harvest when the Pleiades rises (an event which elsewhere is set to mark the end of spring). Such a system was part of general Greek tradition, but fitted to local geography and conditions.

The seasons were not viewed by Greeks as dividing the year into four even blocks, but rather spring and autumn were shorter tail sections of the overarching seasons, Summer and Winter. These divisions could be formalised by using star risings or settings in relation to the equinoxes: so for instance, winter is defined in one medical text as the period between the setting of the Pleiades and the spring.

The older tradition as seen in Hesiod's Works and Days was extended by astronomical research to the creation of star calendars known as parapegmas. These were stone or wooden tablets listing a sequence of astronomical events, each with a peg hole beside it. Lines of bare peg holes were used to count the 'empty days' between what were taken as the significant celestial events. Often set up in town squares (agora), these tablets put the progression of the year on public display.

This system would have been fundamental to an individual's sense of the advancing year, but it barely intersected with the festival or state calendars. These were more civic in character and required managing to maintain their coherence with the year of the seasons. The seasonal and sidereal calendar, on the other hand, was immune to interference. So, Thucydides can date by the rising of the star Arcturus without having to wade into the confusion of disconnected city-state calendars.