The Night Britain Skipped Eleven Days

For most of its history Britain ran on the Julian calendar, which assumed a year of exactly 365.25 days. That figure overshoots the true solar year by roughly 11 minutes, and over many centuries the tiny error compounded until the calendar had slipped a full 11 days out of step with the seasons and with most of Catholic Europe.

Parliament’s solution was the Calendar (New Style) Act 1750, also called Chesterfield’s Act. It legislated a one-time correction: the day after Wednesday, 2 September 1752 would simply be counted as Thursday, 14 September 1752. No British subject lived through 3 to 13 September that year, because by statute those dates never existed.

The days to be numbered as now until 2d Sept. 1752; and the day following to be accounted 14 Sept., omitting 11 days.

The same reform shifted New Year’s Day from 25 March to 1 January and adopted the Gregorian rule that century years are leap years only when divisible by 400. Legend says crowds rioted shouting “Give us our eleven days,” but historians trace that mostly to a satirical Hogarth painting rather than real unrest.