The Midquarter Days are one of the more divisive ideas in archaeoastronomy. The idea was popularised by Alexander Thom, who proposed the year could be divided into eight segments. The solstices and equinoxes divide the year into quarters and a further four festivals in the middle of the quarters sub-divides the year into eight segments. Thom then went further and split the eighths into a year of sixteen ‘months’.
How do you prove this?
It’s easy for relatively recent times as these ‘Midquarter Days’ can still be seen being celebrated today.
May Day coincides with the festival of Beltane. This was said to be the start of summer and can be tracked back in the historical records to the 9th century AD in Irish literature. It was said to be the start of the light half of the year. This was marked by a feast to the fire god. It’s companion festival was Samhain, which survives as Hallowe’en. This was the start of the dark half the year. This can be found on the Coligny Calendar, so it would be reasonable to argue that Beltane also is at least an Iron Age festival.
Archaeological evidence may put the origins of Beltane and Samhain back much further. Following work by Thom a few people have argued that stone rows and circles have not only been aligned on solstices and equinoxes, but also as the rising sun on the midquarter days. Clive Ruggles extensively toured Scotland re-evaluating Thom’s work and rejected this conclusion, but his more recent work in Ireland has been ambiguous, suggesting that there could be marking of some sort around the midquarters.
Whether all four midquarters were the subject of intentional astronomical alignments is difficult to say. Any site orientated to Beltane will automatically be facing the correct direction for Lughnasa (Lammas or August 1). So would a site orientated that way prove that Beltane and Lughnasa existed?
An additional problem is that these festivals were probably not astronomically defined. A solstice has to happen at the astronomically correct time because the Sun is going to change direction whether you want it to or not. A festival like Beltane was more to mark the return of warmer days. In which case it’s foolish to celebrate it if there are still ground frosts, no matter what the Sun is doing. Traditionally Beltane was marked by the flowering of hawthorns. This varies according the to weather that year. As a result you wouldn’t expect an accurate marking of the midquarter days by astronomical alignments in the way that you would with a solstice. If there is such variation, then how do you argue that sites specifically face midquarter days, rather than a general sunrise orientation?
It would be helpful if people wrote down what they did but, by definition, in the prehistoric era this did not happen. The earliest written record we have that is remotely close is the Coligny Calendar, which follows next week.
Part One of A Celtic Calendar was — The ‘Celtic Calendar’ and the Solstices — from May 2
Part Two of A Celtic Calendar — was What is an Equinox? — from May 9
Part Four — The Coligny Calendar- follows on May 23