Читать книгу Out of the Shadow of a Giant: How Newton Stood on the Shoulders of Hooke and Halley - John Gribbin - Страница 7

Until 1752, the English used the old Julian calendar, which was ten days behind the Gregorian calendar (our modern calendar) used across mainland Europe, which had been introduced because the calendar dates on the old calendar had gradually slipped out of sequence with the seasons. Hooke and Halley therefore used Julian (‘Old Style’ or OS) dates, and we have kept these except where we have indicated ‘New Style’ (NS). At the time, the New Year officially began on 25 March, the start of the tax year, but most people, as today, regarded 1 January as the start of the year. Astronomers, in particular, dated the new year from 1 January, and as both Robert Hooke and Edmond Halley were astronomers, that is good enough for us. In some sources, dates between 1 January and 24 March are written with both numbers, as for example 1650/1, but we give all our dates assuming the year began on 1 January.