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.
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 2] (Scotland had already made this aspect of the changes, on 1 January 1600.) [7] [8] The second (in effect [lower-alpha 3] ) 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.
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 4] 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 5] 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]
Through the enactment of the Calendar (New Style) Act 1750, the Kingdom of Great Britain, the Kingdom of Ireland and the British Empire (including much of what is now the eastern part of the United States and Canada) adopted the Gregorian calendar in 1752, by which time it was necessary to correct by 11 days. Wednesday, 2 September 1752, was followed by Thursday, 14 September 1752. Claims that rioters demanded "Give us our eleven days" grew out of a misinterpretation of a painting by William Hogarth. [2]
Beginning in October 1582, the Gregorian calendar replaced the Julian in Catholic countries. This change was implemented subsequently in Protestant and Eastern Orthodox countries, usually at much later dates and, in the latter case, only as the civil calendar. Consequently, when Old Style and New Style notation is encountered, the British adoption date is not necessarily intended. The start-of-the-year change and the calendar system change were not always adopted concurrently. Similarly, civil and religious adoption may not have happened at the same time or even at all. In the case of Eastern Europe, for example, all of those assumptions would be incorrect. Most nations of Europe and their colonies officially adopted 1 January as New Year's Day somewhat before they adopted the Gregorian calendar.
Bulgaria officially adopted the Gregorian calendar on 1 April 1916, which became 14 April 1916. The Bulgarian Orthodox Church adopted the New Julian calendar on 20 December 1968.
France adopted the Gregorian calendar in December 1582. [19] France changed New Year's Day to 1 January from 1564. Previously France had counted various days as New Year's Day: Christmas, Easter-eve, 25 March (Lady Day). [20] [21]
Other countries in Eastern Orthodoxy eventually adopted Gregorian (or New Style) dating for their civil calendars, but most of these continue to use the Julian calendar for religious purposes. Greece was the last European country to change to Gregorian dating for civil purpose, in 1923. [22] There is a 13-day difference between Old Style and New Style dates in modern Greek history.
Romania officially adopted the Gregorian calendar on 1 April 1919, which became 14 April 1919. This was commemorated in 2019 by the National Bank of Romania through the release of a commemorative coin of 10 silver lei. [23]
In Russia, Gregorian calendar dating came into use in early 1918, when 31 January 1918 was followed by 14 February 1918. [24] (There had been a 13-day difference between Julian calendar and Gregorian calendar dates since 1 March 1900.)
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. [25]
In Sweden (and Finland, then part of Sweden) the Gregorian calendar was introduced with effect from 1 March 1753. For practical purposes, the Julian calendar applied until 17 February 1753. The difference between the two calendars was then 11 days, so the next day after 17 February was designated 1 March and thus the eleven days from 18 to 28 February 1753 have never legally existed in Sweden.
In 1700, there was an attempt to gradually introduce the Gregorian calendar in Sweden. The plan was to disregard all leap days from 1700 to 1740 and thereby to reduce the difference between the calendars every four years. However, despite a good start in 1700, the Swedish authorities – due to the Great Northern War – neglected to skip the leap days in 1704 and 1708. As a result, Sweden had its own calendar during that period, called the Swedish calendar and, according to this plan, it would not be until 1748 that the Swedish calendar would coincide with the Gregorian calendar. All of this caused Charles XII to decide, in 1711, that in February 1712 the country would return to the old calendar. This was done by inserting an extra leap day after the regular one that year: Friday, 30 February 1712, the so-called tillökningsdag (supernumerary day). It was to be another 41 years before Sweden attempted the task again.
When, as a result of the Treaty of Fredrikshamn, the Grand Duchy of Finland became part of the Russian Empire on 17 September 1809, Finland reverted to the Julian calendar in compliance with Russian norms. As a result, dates in certain contexts were often entered with both the Old and the New Style.
The European colonies of the Americas adopted the New Style calendar when their mother countries did. In what is now the continental United States, the French and Spanish possessions did so about 130 years earlier than the British colonies. In practice, however, most surviving written records of what is now Canada and the United States are from the 20 mainland British colonies, where the Calendar (New Style) Act 1750 [lower-alpha 6] was applied, twenty-four years before the United States declared independence. Canadian records also include documents of New France that reflect the New Style, as France adopted it in 1582. The language used in the record is likely to be a good indicator of which calendar was being used for the dates given. The same logic applies to the Caribbean islands.
In Alaska, the change took place after the United States purchased Alaska from Russia. Friday, 6 October 1867, was followed by Friday, 18 October. Instead of 12 days, only 11 were skipped, and the day of the week was repeated on successive days, because at the same time the International Date Line was moved, from following Alaska's eastern border with Yukon to following its new western border, now with Russia. [26]
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. [27]
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, [28] 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, [28] 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". [27] 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". [29] 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. [30] 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). [31] The philosopher Jeremy Bentham, born on 4 February 1747/8 (Julian calendar), in later life celebrated his birthday on 15 February. [32]
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 7] a practice that the author Karen Bellenir considered to reveal a deep emotional resistance to calendar reform. [33]
The change 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 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 8] when Russia did so (as its civil calendar) in 1918, thirteen days needed to be skipped.
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". [34] The Latin abbreviations may be capitalised differently by different users, e.g., St.n. or St.N. for stili novi. [34] There are equivalents for these terms in other languages as well, such as the German a.St. ("alter Stil" for O.S.).
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 April 2024" is ten days after "15 April 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.
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.
The Revised Julian calendar, or less formally the new calendar and also known as the Milanković calendar, is a calendar proposed in 1923 by the Serbian scientist Milutin Milanković as a more accurate alternative to both Julian and Gregorian calendars. At the time, the Julian calendar was still in use by all of the Eastern Orthodox Churches and affiliated nations, while the Catholic and Protestant nations were using the Gregorian calendar. Thus, Milanković's aim was to discontinue the divergence between the naming of dates in Eastern and Western churches and nations. It was intended to replace the Julian calendar in Eastern Orthodox Churches and nations. From 1 March 1600 through 28 February 2800, the Revised Julian calendar aligns its dates with the Gregorian calendar, which had been proclaimed in 1582 by Pope Gregory XIII.
The Coptic calendar, also called the Alexandrian calendar, is a liturgical calendar used by the Coptic Orthodox Church and also used by the farming populace in Egypt. It was used for fiscal purposes in Egypt until the adoption of the Gregorian calendar on 11 September 1875. This calendar is based on the ancient Egyptian calendar. To avoid the calendar creep of the latter, a reform of the ancient Egyptian calendar was introduced at the time of Ptolemy III which consisted of adding an extra day every fourth year. However, this reform was opposed by the Egyptian priests, and the reform was not adopted until 25 BC, when the Roman Emperor Augustus imposed the Decree upon Egypt as its official calendar. To distinguish it from the Ancient Egyptian calendar, which remained in use by some astronomers until medieval times, this reformed calendar is known as the Coptic or Alexandrian calendar. Its years and months coincide with those of the Ethiopian calendar but have different numbers and names.
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.
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.
Calendar reform or calendrical reform is any significant revision of a calendar system. The term sometimes is used instead for a proposal to switch to a different calendar design.
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.
Inter gravissimas was a papal bull issued by Pope Gregory XIII on 24 February 1582. The document, written in Latin, reformed the Julian calendar. The reform came to be regarded as a new calendar in its own right and came to be called the Gregorian calendar, which is used in most countries today.
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 rectified other dating anomalies, such as changing 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.
A century leap year is a leap year in the Gregorian calendar that is evenly divisible by 400.
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.
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 was an event in the early modern history of most cultures and societies, marking a change from their traditional dating system to the modern dating system – the Gregorian calendar – that is widely used around the world today. Some states adopted the new calendar from 1582, some did not do so before the early twentieth century, and others did so at various dates between. A few still have not, but except for these, the Gregorian calendar is now the world's civil calendar universally, although in many places an old style calendar remains used in religious or traditional contexts. During – and for some time after – the change 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.