In September 1752, Great Britain changed from the Julian Calendar to the Gregorian Calendar. 11 days were omitted from the calendar. The day after 2 September 1752 became 14 September 1752.
The first day of the year also changed. Prior to 1752 in England, the year began on 25 March (Lady Day).
The first year was short - it ran only from 25 March to 31 December.