Original: In England, the Feast of the Annunciation on March 25, was the first day of the new year until the adoption of the Gregorian Calendar in 1752. The March 25 date was known as Annunciation Style; the January 1 date was known as Circumcision Style, because this was the date of the Feast of the Circumcision, being the eighth day counting from December 25 when Christ was believed to be born.
Simplified: In Annunciation Style dating the new year started on 25 March, the feast of the Annunciation.