Old Style and New Style dates
The first adjusted the start of a new year from 25 March (Lady Day, the Feast of the Annunciation) to 1 January, a change which Scotland had made in 1600.
The consequence was that the basis for the calculation of the date of Easter, as decided in the 4th century, had drifted from reality.
The Gregorian calendar reform also dealt with the accumulated difference between these figures, between the years 325 and 1582, by skipping 10 days to set the ecclesiastical date of the equinox to be 21 March, the median date of its occurrence at the time of the First Council of Nicea in 325.
The first, which applied to England, Wales, Ireland and the British colonies, changed the start of the year from 25 March to 1 January, with effect from "the day after 31 December 1751".
Thus "New Style" can refer to the start-of-year adjustment, to the adoption of the Gregorian calendar, or to the combination of the two.
[f] From 1155 to 1752, the civil or legal year in England began on 25 March (Lady Day);[10][11] so for example, the execution of Charles I was recorded at the time in Parliament as happening on 30 January 1648 (Old Style).
[12] In newer English-language texts, this date is usually shown as "30 January 1649" (New Style).
[3] To reduce misunderstandings about the date, it was normal even in semi-official documents such as parish registers to place a statutory new-year heading after 24 March (for example "1661") and another heading from the end of the following December, 1661/62, a form of dual dating to indicate that in the following twelve weeks or so, the year was 1661 Old Style but 1662 New Style.
Events in Continental Western Europe are usually reported in English-language histories by using the Gregorian calendar.
[22] The Battle of the Boyne in Ireland took place a few months later on 1 July 1690 (Julian calendar).
The latter battle was commemorated annually throughout the 18th century on 12 July,[23] following the usual historical convention of commemorating events of that period within Great Britain and Ireland by mapping the Julian date directly onto the modern Gregorian calendar date (as happens, for example, with Guy Fawkes Night on 5 November).
Letters concerning diplomacy and international trade thus sometimes bore both Julian and Gregorian dates to prevent confusion.
[22] In his biography of John Dee, The Queen's Conjurer, Benjamin Woolley surmises that because Dee fought unsuccessfully for England to embrace the 1583/84 date set for the change, "England remained outside the Gregorian system for a further 170 years, communications during that period customarily carrying two dates".
Many British people continued to celebrate their holidays "Old Style" well into the 19th century,[i] a practice that the author Karen Bellenir considered to reveal a deep emotional resistance to calendar reform.
