Old Style (O.S.) and New Style (N.S.) indicate dating systems before and after a calendar change, respectively. Usually, they refer to the change from the Julian calendar to the Gregorian calendar as enacted in various European countries between 1582 and 1923.
In England, Wales, Ireland and Britain's American colonies, there were two calendar changes, both in 1752. 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 second discarded the Julian calendar in favour of the Gregorian calendar, skipping 11 days in the month of September to do so. [2] [3] To accommodate the two calendar changes, writers used dual dating to identify a given day by giving its date according to both styles of dating.
For countries such as Russia where no start-of-year adjustment took place, [lower-alpha 1] O.S. and N.S. simply indicate the Julian and Gregorian dating systems respectively.
The need to correct the calendar arose from the realisation that the correct figure for the number of days in a year is not 365.25 (365 days 6 hours) as assumed by the Julian calendar but slightly less (c. 365.242 days). The Julian calendar therefore has too many leap years. 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.
Countries that adopted the Gregorian calendar after 1699 needed to skip an additional day for each subsequent new century that the Julian calendar had added since then. When the British Empire did so in 1752, the gap had grown to eleven days; [lower-alpha 2] when Russia did so (as its civil calendar) in 1918, thirteen days needed to be skipped. [lower-alpha 3]
In the Kingdom of Great Britain and its possessions, the Calendar (New Style) Act 1750 introduced two concurrent changes to the calendar. 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". [6] [lower-alpha 4] (Scotland had already made this aspect of the changes, on 1 January 1600.) [7] [8] The second (in effect [lower-alpha 5] ) adopted the Gregorian calendar in place of the Julian calendar. 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. It was through their use in the Calendar Act that the notations "Old Style" and "New Style" came into common usage.
When recording British history, it is usual to quote the date as originally recorded at the time of the event, but with the year number adjusted to start on 1 January. [9] The latter adjustment may be needed because the start of the civil calendar year had not always been 1 January and was altered at different times in different countries. [lower-alpha 6] 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). [13] The corresponding date in the Gregorian calendar is 9 February 1649, the date by which his contemporaries in some parts of continental Europe would have recorded his execution.
The O.S./N.S. designation is particularly relevant for dates which fall between the start of the "historical year" (1 January) and the legal start date, where different. This was 25 March in England, Wales, Ireland and the colonies until 1752, and until 1600 in Scotland.
In Britain, 1 January was celebrated as the New Year festival from as early as the 13th century, despite the recorded (civil) year not incrementing until 25 March, [14] [lower-alpha 7] but the "year starting 25th March was called the Civil or Legal Year, although the phrase Old Style was more commonly used". [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. [17] Some more modern sources, often more academic ones (e.g. the History of Parliament) also use the 1661/62 style for the period between 1 January and 24 March for years before the introduction of the New Style calendar in England. [18] [9]
The Gregorian calendar was implemented in Russia on 14 February 1918 by dropping the Julian dates of 1–13 February 1918, [lower-alpha 8] pursuant to a Sovnarkom decree signed 24 January 1918 (Julian) by Vladimir Lenin. The decree required that the Julian date was to be written in parentheses after the Gregorian date, until 1 July 1918. [19]
It is common in English-language publications to use the familiar Old Style and/or New Style terms to discuss events and personalities in other countries, especially with reference to the Russian Empire and the very beginning of Soviet Russia. For example, in the article "The October (November) Revolution", the Encyclopædia Britannica uses the format of "25 October (7 November, New Style)" to describe the date of the start of the revolution. [20]
The Latin equivalents, which are used in many languages, are, on the one hand, stili veteris (genitive) or stilo vetere (ablative), abbreviated st.v., and meaning "(of/in) old style"; and, on the other, stili novi or stilo novo, abbreviated st.n. and meaning "(of/in) new style". [21] The Latin abbreviations may be capitalised differently by different users, e.g., St.n. or St.N. for stili novi. [21] There are equivalents for these terms in other languages as well, such as the German a.St. ("alter Stil" for O.S.).
Usually, the mapping of New Style dates onto Old Style dates with a start-of-year adjustment works well with little confusion for events before the introduction of the Gregorian calendar. For example, the Battle of Agincourt is well known to have been fought on 25 October 1415, which is Saint Crispin's Day. However, for the period between the first introduction of the Gregorian calendar on 15 October 1582 and its introduction in Britain on 14 September 1752, there can be considerable confusion between events in Continental Western Europe and in British domains. Events in Continental Western Europe are usually reported in English-language histories by using the Gregorian calendar. For example, the Battle of Blenheim is always given as 13 August 1704. However, confusion occurs when an event involves both. For example, William III of England arrived at Brixham in England on 5 November (Julian calendar), after he had set sail from the Netherlands on 11 November (Gregorian calendar) 1688. [22]
The Battle of the Boyne in Ireland took place a few months later on 1 July 1690 (Julian calendar). That maps to 11 July (Gregorian calendar), conveniently close to the Julian date of the subsequent (and more decisive) Battle of Aughrim on 12 July 1691 (Julian). 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). The Battle of the Boyne was commemorated with smaller parades on 1 July. However, both events were combined in the late 18th century, [23] and continue to be celebrated as "The Twelfth".
Because of the differences, British writers and their correspondents often employed two dates, a practice called dual dating, more or less automatically. Letters concerning diplomacy and international trade thus sometimes bore both Julian and Gregorian dates to prevent confusion. For example, Sir William Boswell wrote to Sir John Coke from The Hague a letter dated "12/22 Dec. 1635". [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". [24] In contrast, Thomas Jefferson, who lived while the British Isles and colonies converted to the Gregorian calendar, instructed that his tombstone bear his date of birth by using the Julian calendar (notated O.S. for Old Style) and his date of death by using the Gregorian calendar. [25] At Jefferson's birth, the difference was eleven days between the Julian and Gregorian calendars and so his birthday of 2 April in the Julian calendar is 13 April in the Gregorian calendar. Similarly, George Washington is now officially reported as having been born on 22 February 1732, rather than on 11 February 1731/32 (Julian calendar). [26] The philosopher Jeremy Bentham, born on 4 February 1747/8 (Julian calendar), in later life celebrated his birthday on 15 February. [27]
There is some evidence that the calendar change was not easily accepted. Many British people continued to celebrate their holidays "Old Style" well into the 19th century, [lower-alpha 9] a practice that the author Karen Bellenir considered to reveal a deep emotional resistance to calendar reform. [28]
A calendar date is a reference to a particular day represented within a calendar system. The calendar date allows the specific day to be identified. The number of days between two dates may be calculated. For example, "25 October 2024" is ten days after "15 October 2024". The date of a particular event depends on the observed time zone. For example, the air attack on Pearl Harbor that began at 7:48 a.m. Hawaiian time on 7 December 1941 took place at 3:18 a.m. Japan Standard Time, 8 December in Japan.
The Julian calendar is a solar calendar of 365 days in every year with an additional leap day every fourth year. The Julian calendar is still used as a religious calendar in parts of the Eastern Orthodox Church and in parts of Oriental Orthodoxy as well as by the Amazigh people.
A leap year is a calendar year that contains an additional day compared to a common year. The 366th day is added to keep the calendar year synchronised with the astronomical year or seasonal year. Since astronomical events and seasons do not repeat in a whole number of days, calendars having a constant number of days each year will unavoidably drift over time with respect to the event that the year is supposed to track, such as seasons. By inserting ("intercalating") an additional day—a leap day—or month—a leap month—into some years, the drift between a civilization's dating system and the physical properties of the Solar System can be corrected.
The New Year is the time or day at which a new calendar year begins and the calendar's year count increments by one. Many cultures celebrate the event in some manner. In the Gregorian calendar, the most widely used calendar system today, New Year occurs on January 1. This was also the first day of the year in the original Julian calendar and the Roman calendar.
In the Western liturgical year, Lady Day is the common name in some English-speaking and Scandinavian countries of the Feast of the Annunciation, celebrated on 25 March to commemorate the annunciation of the archangel Gabriel to the Virgin Mary that she would bear Jesus Christ, the Son of God.
In the Gregorian calendar, New Year's Day is the first day of the calendar year, 1 January. Most solar calendars begin the year regularly at or near the northern winter solstice, while cultures and religions that observe a lunisolar or lunar calendar celebrate their Lunar New Year at less fixed points relative to the solar year.
The Soviet calendar was a modified Gregorian calendar that was used in Soviet Russia between 1918 and 1940. Several variations were used during that time.
As a moveable feast, the date of Easter is determined in each year through a calculation known as computus. Easter is celebrated on the first Sunday after the Paschal full moon. Determining this date in advance requires a correlation between the lunar months and the solar year, while also accounting for the month, date, and weekday of the Julian or Gregorian calendar. The complexity of the algorithm arises because of the desire to associate the date of Easter with the date of the Jewish feast of Passover which, Christians believe, is when Jesus was crucified.
The Swedish calendar or Swedish style was a calendar in use in Sweden and its possessions from 1 March 1700 until 30 February 1712. It was one day ahead of the Julian calendar and ten days behind the Gregorian calendar. Easter was calculated astronomically, with a minor exception, from 1740 to 1844.
The epact used to be described by medieval computists as the age of a phase of the Moon in days on 22 March; in the newer Gregorian calendar, however, the epact is reckoned as the age of the ecclesiastical moon on 1 January. Its principal use is in determining the date of Easter by computistical methods. It varies from year to year, because of the difference between the solar year of 365–366 days and the lunar year of 354–355 days.
Dominical letters or Sunday letters are a method used to determine the day of the week for particular dates. When using this method, each year is assigned a letter depending on which day of the week the year starts. The Dominical letter for the current year 2024 is GF.
The determination of the day of the week for any date may be performed with a variety of algorithms. In addition, perpetual calendars require no calculation by the user, and are essentially lookup tables. A typical application is to calculate the day of the week on which someone was born or a specific event occurred.
The Eastern Orthodox liturgical calendar describes and dictates the rhythm of the life of the Eastern Orthodox Church. Passages of Holy Scripture, saints and events for commemoration are associated with each date, as are many times special rules for fasting or feasting that correspond to the day of the week or time of year in relationship to the major feast days.
The Calendar Act 1750, also known as Chesterfield's Act or the British Calendar Act of 1751, is an Act of the Parliament of Great Britain. Its purpose was for Great Britain and the British Empire to adopt the Gregorian calendar. The Act also changed the start of the legal year from 25 March to 1 January.
Dual dating is the practice, in historical materials, of indicating a date with what appear to be duplicate or excessive digits: these may be separated by a hyphen or a slash, or placed one above the other. The need for dual dating arose from the transition from an older calendar to a newer one. Another method used is to give the date of an event according to one calendar, followed in parentheses by the date of the same event in the other calendar, appending an indicator to each to specify which reference calendar applies.
The Gregorian calendar is the calendar used in most parts of the world. It went into effect in October 1582 following the papal bull Inter gravissimas issued by Pope Gregory XIII, which introduced it as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years differently so as to make the average calendar year 365.2425 days long, more closely approximating the 365.2422-day 'tropical' or 'solar' year that is determined by the Earth's revolution around the Sun.
The proleptic Gregorian calendar is produced by extending the Gregorian calendar backward to the dates preceding its official introduction in 1582. In nations that adopted the Gregorian calendar after its official and first introduction, dates occurring in the interim period of 15 October 1582 to the date on which the pertinent nation adopted the Gregorian calendar and abandoned the Julian calendar are sometimes 'Gregorianized' also. For example, the birthday of U.S. President George Washington was originally dated 11 February 1731 because Great Britain, of which he was born a subject, used the Julian calendar and dated the beginning of English years as 25 March. After Great Britain switched to the Gregorian calendar, Washington's birthday was dated 22 February 1732 proleptically, according to the Gregorian calendar applied backward. This remains the modern dating of his birthday.
The regnal years of English and British monarchs are the official regnal years of the monarchs of the Kingdom of England from 1066 to May 1707, the Kingdom of Great Britain from May 1707 to January 1801, and the United Kingdom since January 1801. The regnal calendar continues to be utilized in many official British government and legal documents of historical interest, notably parliamentary statutes prior to 1963, and prior to 1867 in the case law collected in the year books, nominative reporters, and digests, and in the reports republished in the English Reports and Revised Reports. In legal citation, the first monarch of a regnal name is not followed by an ordinal number, but all subsequent monarchs of that name are. Thus, the 25th year of Elizabeth I is simply 25 Eliz., but the 25th year of Elizabeth II is 25 Eliz. 2.
This is the calendar for Old Style 1752, a leap year which began on 1 January, and dropped 3–13 September to transition to the Gregorian calendar. Previously, the Old Style calendar in England had begun on 25 March and ended with the following March, on 24 March. Because the Gregorian calendar did not have leap day in 1700, the original 10-day difference in calendars had expanded to an 11-day difference, and to compensate, 2 September was followed by 14 September, as skipping 11 days beyond 3 September. Year 1753, in England followed the full Gregorian calendar. Note, below, the shortened length of September.
The adoption of the Gregorian Calendar has taken place in the history of most cultures and societies around the world, marking a change from one of various traditional dating systems to the contemporary system – the Gregorian calendar – which is widely used around the world today. Some states adopted the new calendar in 1582, others not before the early twentieth century, and others at various dates between. A few have yet to do so, but except for these, the Gregorian calendar is now the world's universal civil calendar, old style calendars remaining in use in religious or traditional contexts. During – and for some time after – the transition between systems, it has been common to use the terms "Old Style" and "New Style" when giving dates, to indicate which calendar was used to reckon them.
Dates are Old Style, but the year is calculated from 1 January. On occasion, where clarity requires it, dates are written 1687/8.
God's-daddikins! it is my birthday – say something pretty to me on the occasion.