On September 2, 1752, Britain and its American colonies dropped eleven days from the calendar, going to bed on Wednesday the 2nd and waking on Thursday the 14th. The Calendar (New Style) Act 1750 replaced the Julian calendar with the Gregorian one that most of Catholic Europe had used since 1582.
The Julian year ran about eleven minutes longer than the solar year. That small error added up. By the 1750s the calendar had drifted eleven days out of line, and the spring equinox fell around March 10 instead of March 21, which dragged the date of Easter off with it. The fix had two halves: centenary years would count as leap years only when divisible by 400, and the accumulated error would be cancelled by skipping eleven days in September.
Britain had resisted for nearly two centuries, partly because the reform carried the name of a pope. The push came from Philip Stanhope, 4th Earl of Chesterfield, with astronomical work by George Parker, 2nd Earl of Macclesfield. The Act also moved the start of the year from March 25 to January 1, so 1751 ran for only 282 days.
Protest followed. Some called it popery. Others thought the government had stolen eleven days of their lives, and the slogan "give us our eleven days" was still being used in the 1754 election. Most historians now think the riots were exaggerated. One trace survives in Britain: the tax year still ends on April 5, because officials refused to lose eleven days of revenue.