The date of the new year has changed throughout history From the 6th century until 1066 it ran from Christmas Day (December 25) From the 1067 until 1155 it ran from 1st January to 31st December From 1155 to 1751 25th March to the 24th March In 1751 the dates between In 1751 it ran from 25th March to 31st December. From 1st January 1752 to the present day it ran from 1st Jan to 31st December This brings problems for family historians especially for the period 1155 to 1751. This is overcome by using the system known as double dating for the months January, February and March. I.E. the date 25 January 1748/9 signifies the day occurs in the year we know call 1749. This is further complicated by some source pre-empted the change of calendar and recorded the year starting on January 1st before the official change on 1st January 1751. This may be determined by viewing the full register or source rather than simply viewing an individual record.