The Celts apparently celebrated 1st November as the start of their year. One website I found states:-
“November 1 is the Celtic feast of Samhain. Samhain, Gaelic for “summer’s end,” was the most important of the ancient Celtic feasts.
The Celts honored the opposing balance of intertwining forces of existence: darkness and light, night and day, cold and heat, death and life. The Celtic year was divided into two seasons: the light and the dark, celebrating the light at Beltane on May 1st and the dark at Samhain on November 1st.
Therefore, the Feast of Samhain marks one of the two great doorways of the Celtic year. Some believe that Samhain was the more important festival, since it marked the beginning of a new dark-light cycle. The Celts observed time as proceeding from darkness to light because they understood that in dark silence comes whisperings of new beginnings, the stirring of the seed below the ground. Therefore, the Celtic year began with the season of An Geamhradh, the dark Celtic winter, and ended with Am Foghar, the Celtic harvest.”
If this was the case, then there would have been plenty of celebrations in the so-called "New City" of Milton Keynes on this day a couple of thousand years ago. When our new city was being built, archaeologists were given a great opportunity to discover our ancient history. There were a number of iron age sites – including a settlement in the centre of Furzton (where I live); and close to the site of the Roman Villa in Bancroft.
The map below (from Croft and Mycroft’s excellent “The Changing Landscape of Milton Keynes” [copies available for loan from the libraries at Bletchley; Stony Stratford; Wolverton; and Woburn Sands – and at the MK Local Studies Library in the Central Library]) show the main sites. You may be able to enlarge the picture by clicking on it.