There was no single Greek scheme
Modern readers tend to expect four neat seasons of equal length, each starting on a set date. Ancient Greeks did not work that way, and the evidence shows several overlapping systems. Seasons were reckoned by what farmers did, by the rising and setting of stars, by religious festivals and, in medical writing, by the effects of weather on the body. There were also no uniform political calendars: each city had its own month names and its own way of starting the year.
Because of this, the number of seasons depends on the writer. Sources commonly speak of winter (cheimon), spring (ear) and summer (theros), with a fourth period, opora, covering late summer and early autumn, the time of ripening fruit. Others treat autumn (phthinoporon) as a separate season, and some texts use a simple split between a warm and a cold half of the year. So “three or four seasons” is a fair summary of the variation, not a flaw in the sources.
Hesiod and the farming year
The earliest extended seasonal guide in Greek is Hesiod’s Works and Days, a poem usually dated to around 700 BCE. Hesiod, a farmer-poet from Boeotia, tells his brother when to carry out the main tasks. He ties them to stars rather than dates. The heliacal rising of the Pleiades, their first visible appearance before dawn, signals the start of harvest, and their setting signals the time for ploughing and sowing. The rising of Arcturus and later of Sirius mark pruning and the hottest part of summer.
Because the stars return to the same position each year, they gave farmers a reliable calendar even when the civic months drifted. Modern dating of these risings in the Greek world places the Pleiades’ morning rising roughly in May and their setting in late autumn, but the exact timing varied by latitude and by the centuries involved. Hesiod also describes the grim midwinter weather and advises on clothing, ships and food. For him, sailing was safe only in a short window of summer, a view that matches what is known about Mediterranean seafaring risks.
Star calendars and civic months
Later Greek astronomers compiled parapegmata, tables or inscribed stone slabs that matched star risings and settings to weather expectations. Some were fixed to public buildings in cities. They show that observation of the sky stayed useful for farming and travel long after formal calendars existed. The tradition has similarities with Babylonian astronomy, from which Greek astronomers drew some data and methods, though the transmission happened gradually and some details are debated.
Civic calendars were lunar, with months of about 29 or 30 days, and needed periodic adjustment to keep the festivals in the right season. In Athens, month names such as Thargelion and Pyanepsion were tied to particular rites. The extra month used to correct the drift was not always inserted on a fixed schedule, which is one reason the same date in two cities may fall in different parts of the year. Our best-known Athenian cycle belongs to the Classical period, and even there the details remain debated.
Festivals and the turning year
Religious festivals gave the seasons a social shape. Agricultural cycles were honoured in rites such as the Thesmophoria, which women celebrated in autumn in connection with Demeter and the sowing of grain, and the Dionysian festivals of winter and spring, during which wine, theatre and processions marked the end of the cold months. Harvest and first-fruit offerings accompanied late summer and autumn. The Greek festival year therefore worked as a calendar of memory as well as a record of dates. The Romans later built a similar structure in their own festival calendar, though with different gods and rules.
Seasons, climate and health
Greek medicine treated the seasons as a cause of disease. The Hippocratic text Airs, Waters, Places advises physicians arriving in a new city to consider its seasons, winds, water sources and orientation, because these shape common illnesses. Other Hippocratic writings describe how changes in weather may bring particular diseases, and advise regimen, meaning diet and exercise, adjusted for each time of year. In the Hippocratic Corpus, there is no single doctrine on every point, and the works come from different authors.
This line of thought fed into the humoral theory, in which each humour was linked to a season, for example blood with spring and black bile with autumn in some later versions. These pairings come from later schemes and should not be projected back onto early Greek farmers. They are better understood as medical attempts to give order to experience, and they were not used by ordinary people to organise the working year.
Why it matters
The Greek seasons show how people with no common calendar still coordinated work, religion and health. A farmer watched the dawn sky, a city official followed the moon, a doctor looked at winds and water. All of them were reading the same year, from different angles. Understanding that variety is a useful corrective to the idea that ancient societies had one fixed model of time.