Adoption of the Gregorian calendar the Empire (except Scotland, which had already done so from 1600) changed the start of the civil year from 5 April to 1 January. Consequently, the custom of dual dating (giving a date in both old and new styles) can refer to the Julian/Gregorian calendar change, or to the start of year change, or to both. The British tax year traditionally began on Lady Day (25 March) on the Julian calendar and thus became 5 April, which was the "Old Style" equivalent. A 12th skipped Julian leap day in 1800 changed its start to 6 April. It was not changed
Adoption of the Gregorian calendar the date of Easter astronomically using the instant of the vernal equinox and the full moon according to Kepler's "Rudolphine Tables" of 1627; this combination was referred to by the Protestant estates as the "improved calendar" ("Verbesserte Kalender") and considered to be distinct from the Gregorian. They finally adopted the Gregorian calculation of Easter in 1774. The remaining provinces of the Dutch Republic adopted the Gregorian calendar on 12 July 1700 (Gelderland), 12 December 1700 (Overijssel and Utrecht), 12 January 1701 (Friesland and Groningen) and 12 May 1701 (Drenthe). Sweden's transition to the Gregorian calendar was difficult and protracted. Sweden