Seasonal animal migrations gave hunters a reason to follow the course of the year. And once humans learned to farm the land, keeping track of time became even more important. One of the earliest pieces of evidence for this may be the Neolithic monument of Stonehenge in England. It’s clear that humans of the past kept track of the sunrise at summer and winter solstices there. But it’s hard to say now, 5000 years later, whether it functioned as a more complex calendar, or merely as a focal point for a solar cult.
But calendars and cults are often closely connected. All civilisations try to predict in advance when holidays and ceremonies will take place, and these are often tied to astronomical events. The Jews and ancient Greeks made their calendars so that some festivals always took place at full moon. Christians still move one of their most important holidays, Easter, depending on the full moon and equinox.
A calendar is a plan for the year, a complete cycle of the seasons. It might relate to lunar
