Why Britain Lost Eleven Days in 1752

When Pope Gregory XIII reformed the calendar in 1582, Protestant England had no intention of following a papal decree. For 170 years Britain and its colonies kept the Julian calendar while most of continental Europe used the Gregorian, so a letter sent from London to Paris could arrive, by the local calendar, before it was sent. Merchants and diplomats routinely wrote both dates, Old Style and New Style.

By the eighteenth century the gap had grown to eleven days, and Protestant Germany and Denmark had already switched in 1700. The Calendar (New Style) Act 1750, steered through Parliament by the Earl of Chesterfield, settled the matter: Wednesday 2 September 1752 was followed by Thursday 14 September. The weekday sequence was unbroken; only the dates jumped.

The same act moved the legal start of the year in England from Lady Day, 25 March, to 1 January. That is why 1751 was a short year, running only from 25 March to 31 December, and why historians write dates such as 24 March 1749/50 for the old January to March period. Scotland had already begun its year on 1 January since 1600.

Some traces survive. The British tax year, once aligned to Lady Day, absorbed the lost days and now begins on 6 April. The popular story of crowds rioting to demand their eleven days back is mostly a later legend, built partly on a satirical Hogarth painting, but the confusion over rents, wages and birthdays was real enough.