For the ancient-Europeans, the year began with the winter, just as the day began with the eve. It is generally true that day-frost has come, by the Gregorian calendar, some time around the beginning of November. The deer are finishing their mating, the salmon are finishing their laying of eggs, and the oaks are dropping their acorns. In Irish, this time is called Samhain, thought to mean summer's end.
At the same time, the willow-withies have grown to their yearly longest and sloe-fruits are becoming edible on the blackthorn trees. The turning-of-the-seasons occurs as plants and animals interact with the weather.
The experience of the first day-frosts is an unmistakable cue for many wild things living out in the world. Many Winters have passed since large groups of people reckoned this as the beginning of the year. Still, some few people continue to respond to the first frosts felt during the day as the year's beginning.