Old Style and New Style dates

Old Style (or O.S.) and New Style (or N.S.) are used in English language historical studies either to indicate that the start of the Julian year has been adjusted to start on 1 January (N.S.) even though contemporary documents use a different start of year (O.S.); or to indicate that a date conforms to the Julian calendar (O.S.), formerly in use in many countries, rather than the Gregorian calendar (N.S.).

The Gregorian calendar replaced the Julian in Catholic countries beginning in 1582. This change was also implemented in Protestant and Orthodox countries after a significant delay. In England and Wales, Ireland and the British colonies, the change of the start of the year and the change over from the Julian calendar occurred in 1752 via the Calendar (New Style) Act 1750. In Scotland, the legal start of the year had already been moved to 1 January (in 1600), but Scotland otherwise continued to use the Julian Calendar until 1752. Many cultures and countries now using the Gregorian calendar have different old styles of dating, depending on the type of calendar they used before the change.

The internationally used Latin cognates of O.S. are stili veteris or stilo vetere, abbreviated st.v. and translating as "(of) old style", and the respective cognates of N.S. are stili novi or stilo novo, abbreviated st.n. and translating as "(of) new style". Like the English speaking countries, other countries may use additional local language cognates like the German a.St. ("alten Stils" for O.S.). Also, parts of the Latin abbreviations may be capitalized, e.g., St.n. or St.N. for stili novi. so for example the execution of Charles I was recorded at the time in Parliament as happening on 30 January 1648 (Old Style). In modern English-language texts this date is usually recorded as "30 January 1649" (New Style). but the "year starting 25th March was called the Civil or Legal Year, although the phrase Old Style was more commonly used."

Differences between Julian and Gregorian dates

The Julian calendar was formerly in use in many European countries and their colonies, rather than the Gregorian calendar, currently in use in most countries. Consequently and to avoid ambiguity, "Old Style" (O.S.) and "New Style" (N.S.) are sometimes added to historical dates to identify which system is being used (when giving a date in the period when both systems were in parallel use). This notation is used in Western European (and colonial) history: similar notations are in use for the equivalent conversions in Eastern Europe and Asia.

For a period of 170 years (1582–1752), both dating systems were in concurrent use in different parts of Western Europe and its colonies. The Julian calendar had drifted by 11 days from the solar calendar (due to its excess of leap years), so dates differ between the systems. System conversion for secular use occurred in Eastern Orthodox countries as late as the 20th century, and has still not occurred for ecclesiastic use in some of these countries.

Catholic countries such as Italy, Poland, Spain, and Portugal were first to change to the Gregorian calendar. Thursday, 4 October 1582 was followed by Friday, 15 October 1582, with ten days "missing". Countries that did not change until the 18th century observed an additional leap year, necessitating eleven "missing days". Some countries did not change until the 19th or 20th century, necessitating one or two more "missing days".

France changed from Julian to Gregorian Calendar on 9 December 1582 (O.S.) where the next day was 20 December 1582 (N.S.). France used the French Republican Calendar from 22 September 1792 (N.S.) to 31 December 1805 (N.S.).

Ireland, (and under the provisions of the Calendar (New Style) Act 1750), Great Britain and the British colonies, changed from Julian to Gregorian Calendar at midnight on Wednesday 2 September 1752, the next day was Thursday 14 September 1752.

In Russia, the terms "Old Style" and "New Style" have the same significance as elsewhere. The start of the year was moved to 1 January in 1700, but the Gregorian calendar was introduced there much later, on 14 February 1918 (Gregorian calendar) in Soviet Russia (which became the Soviet Union in 1922). Hence the October Revolution of 1917 is so called, despite having started on 7 November under the Gregorian calendar (25 October [Julian calendar]). Articles about the October Revolution which mention this date difference tend to do a full conversion to the dates from Julian to the Gregorian calendar. For example 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.

It is sometimes remarked that William Shakespeare and Miguel de Cervantes died on the same date, 23 April 1616, but not on the same day. England was still using the Julian calendar in 1616, while Spain was using the Gregorian calendar. Cervantes actually died ten days before Shakespeare.

Possible date conflicts

, covering Great Britain's switch from O.S. to N.S.]] Occasionally using different calendars has caused confusion between contemporaries. For example, it is related that one of the contributory factors for Napoleon's victory at the Battle of Austerlitz was the confusion between the Russians, who were using the Julian calendar, and the Austrians, who were using the Gregorian calendar, over the date that their forces should combine. However, this tale is not supported in a contemporary account from a major-general of the Austrian army, who tells of a joint advance of the Russian and Austrian forces (in which he himself took part) five days before the battle, and it is explicitly rejected in Goetz's recent book-length study of the battle.

Usually, the mapping of new dates onto old dates with a start of year adjustment works well with little confusion for events which happened before the introduction of the Gregorian Calendar. For example the Battle of Agincourt is universally known to have been fought on 25 October 1415, which is Saint Crispin's Day. But 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 as happening under the Gregorian calendar. For example the Battle of Blenheim is always given as 13 August 1704. However confusion occurs when an event affects both. For example William III of England arrived at Brixham in England on 5 November (Julian calendar), after setting sail from the Netherlands on 11 November (Gregorian calendar).

The Battle of the Boyne took place only a few months later in Ireland on 1 July 1690 "Old Style". However, it is commemorated as taking place on 12 July "New Style" by the Orange parades on "The Twelfth", and is an exception to the usual historical method of commemorating events of that period within Great Britain and Ireland by mapping the Julian date directly onto the modern Gregorian calendar (as happens for example with Guy Fawkes Night on 5 November).

. tombstone. Written below the epitaph is "BORN APRIL 2 1743 O.S. DIED JULY 4 1826"]] Because of the differences, English people and their correspondents often employed two dates, dual dating, more or less automatically, as Benjamin Woolley observed in his biography of Dr John Dee, The Queen's Conjurer. Dee fought unsuccessfully for England to embrace the 1583/4 date set for the change. Woolley wrote because of "the decision, England remained outside the Gregorian system for a further 170 years, communications during that period customarily carrying two dates, one 'O.S.' or Old Style, the other 'N.S.' or New Style." Thomas Jefferson, for example, lived during the time Great Britain, Ireland and the British colonies eventually converted to the Gregorian calendar, so he instructed that his tombstone bear his dates of birth and death in the Old Style and New Style, respectively. At Jefferson's birth the difference would have been eleven days between styles, had the New Style been converted to yet, as is evidenced by his "original" birthday of 2 April and his New Style birthday of 13 April.

Countries that used lunisolar calendars

Japan, Korea, and China started using the Gregorian calendar on 1 January 1873, 1896, and 1912, respectively. They had used lunisolar calendars previously. None of them used the Julian calendar; the Old Style and New Style dates in these countries usually mean the older lunisolar dates and the newer Gregorian calendar dates respectively. In these countries, the old style calendars were similar but not all the same. The Arabic numerals may be used for both calendar dates in modern Japanese and Korean languages, but not Chinese.

Japan

Japan started using the Gregorian calendar on 1 January 1873, locally known as . The preceding day, 31 December 1872, was .

Japan currently uses two eras: The Western era and a modified traditional Japanese era name (nengō). The months and days are those of the Gregorian calendar, but the year is either the Western year number or a year of the nengō of the emperor on the throne. Since 1873, an era and the first year of that era has begun on the day of the year that the emperor ascended the throne. The second year of that era began on the next 1 January even if the first year contained only a few days. All subsequent years of that era began on 1 January until that emperor died. For example, the first year of the Showa Era, used by Emperor Hirohito, contained only the last six days of 1926, while Showa 64, his last year, contained only the first seven days of 1989. The current Gregorian year corresponds to Heisei -1988}}.

Korea

Korea started using the Gregorian calendar on 1 January 1896, which was the 17th day of the 11th lunar month in not only Korea but also in China that still used the lunisolar calendar. The lunisolar Korean calendar is now used in very limited unofficial purposes only. In North Korea, the New Style calendar is used, but with Kim Il-Sung's year of birth used as year 0.

China and Taiwan

The Republic of China started using the Gregorian calendar on 1 January 1912, but the lunisolar Chinese calendar is still used along with the Gregorian calendar, especially when determining certain traditional holidays. The reference has been a longitude of 120°E since 1929, which is also used for China standard time (UTC+8). China, Hong Kong, Macau, Malaysia, Indonesia, Singapore and Taiwan all have legal holidays based on the lunisolar Chinese calendar, with the most important one being the Chinese New Year. When the People's Republic of China took power in the late 1940s they kept the system of the Gregorian Calendar alongside the Chinese calendar.

To visually distinguish old and new style dates, GB/T 15835-1995, General rules for writing numerals in publications, which is a national standard of the People's Republic of China, requires writing new style dates with Arabic numerals but old style dates with Chinese characters, never Arabic numerals.

In Taiwan, even though new style dates are written in Chinese characters in very formal texts, it is now common to see Arabic numerals in new style dates in less formal texts. When writing old style dates, Chinese characters are usually used while Arabic numerals are considered very casual and strongly discouraged as in Mainland China. The calendar year in Taiwan is usually expressed as the "Year of the Republic"—counting Year 1 as the foundation of the Republic of China in 1912.

Notes and references

Further reading

Details of conversion for many countries

Side-by-side Old style–New style reference

Time to Take Note: The 1752 Calendar Change from Ancestry.com

Calendar Converter Date converter for many systems, from John Walker

Category:Timekeeping Category:Time in the United Kingdom