Old Style (or OS) and New Style (or NS) 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 (NS) even though contemporary documents use a different start of year (OS); or to indicate that a date conforms to the Julian calendar (OS), formerly in use in many countries, rather than the Gregorian calendar (NS). The Julian calendar, a reform of the Roman calendar, was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 Ab urbe condita New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC The Julian calendar, a reform of the Roman calendar, was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 Ab urbe condita The Gregorian calendar is the most widely used Calendar in the world today  In Great Britain and the British colonies the change of start of the year and the change over from the Julian calendar occurred in 1752 and was enabled by the Calendar (New Style) Act 1750. The Kingdom of Great Britain, also known as the United Kingdom of Great Britain, was a State in northwest Europe, in existence from 1707 to 1800 See also Old Style and New Style dates See also Gregorian calendar, Julian calendar The Calendar (New Style Act 1750 (also known as 
When recording British history it is usual to use the dates recorded at the time of the event with the year adjusted to the start on the 1 January. New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC So for example the Battle of Hastings is universally known to have been fought on 14 October 1066. The Battle of Hastings was the decisive Norman victory in the Norman Conquest of England. Events 1066 - Norman Conquest: Battle of Hastings - In England on Senlac Hill seven miles from Hastings, the forces But the start of the Julian year was not always 1 January and was altered at different times in different countries. The Julian calendar, a reform of the Roman calendar, was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 Ab urbe condita New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC
From the 12th century to 1752, the civil or legal year in England began on 25 March (Lady Day) so for example the execution of Charles I was recorded at the time in Parliament as happening on 30 January 1648 (Old Style). Events 1199 - Richard I is wounded by a crossbow bolt while fighting France which leads to his death on April 6. In the Christian calendar, Lady Day is the Feast of the Annunciation ( 25 March) and the first of the four traditional Irish and Charles I, (19 November 1600 &ndash 30 January 1649 was King of England, Scotland and Ireland from 27 March 1625 until his execution. Events 1648 - Eighty Years' War: The Treaty of Münster is signed ending the conflict between the Netherlands and Spain  In modern English language texts this date is usually recorded as "30 January 1649" (New Style).  A full conversion of the date into the Gregorian calendar is 9 February 1649, the date by which his contemporaries in some parts of continental Europe would have recorded his execution. Events 474 - Zeno crowned as co-emperor of the Byzantine Empire.
The OS/NS designation is particularly relevant for dates which fall between the start of the modern year (1 January) and the start of the contemporary year, which was 25 March in England up until 1752 (see Julian year article). New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Events 1199 - Richard I is wounded by a crossbow bolt while fighting France which leads to his death on April 6. The Julian calendar, a reform of the Roman calendar, was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 Ab urbe condita
During the transition years between the first introduction of the Gregorian calendar on continental Europe and its introduction in Britain, contemporary usage in England started to change.  In Britain 1 January was celebrated as the New Year festival, but the "year starting 25th March was called the Civil or Legal Year, although the phrase Old Style was more commonly used. New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC " To reduce misunderstandings on the date, it was normal in parish registers for a new year heading after 24 March, for example 1661 had another heading at the end of the following December indicating "1661/62". Events 1401 - Mongol emperor Timur sacks Damascus. 1603 - James VI of Scotland This was to explain to the reader that the year was 1661 Old Style and 1662 New Style. 
|Time period (from March 1 of first year to February 29 of last year)||Сorrection, days|
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. Events 86 BC - Lucius Cornelius Sulla, at the head of a Roman Republic army enters in Athens, removing the Tyrant Leap years Although the modern calendar counts a year as 365 days a complete revolution around the sun takes approximately 365 days and 6 hours The Julian calendar, a reform of the Roman calendar, was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 Ab urbe condita The Gregorian calendar is the most widely used Calendar in the world today Consequently and to avoid ambiguity, "Old Style" (OS) and "New Style" (NS) 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 surfeit of leap years), so the day and month differ between the systems as well as does the year. System conversion for secular use occurred in Eastern Orthodox countries as late as the twentieth century, and has still not occurred for ecclesiastic use in some of these countries. The Eastern Orthodox Church is the second largest single Christian Communion in the world
Catholic countries such as Italy, Poland, Spain, and Portugal were first to change to the Gregorian calendar. The Polish–Lithuanian Commonwealth, officially the Commonwealth of the Crown of the Polish Kingdom and the Grand Duchy of Lithuania also known as the Most Serene Republic Habsburg Spain refers to the history of Spain over the 16th and 17th centuries (1516-1700 when this country was ruled by the Habsburg dynasty (also associated to Iberian Union is a modern day term that refers to the historical political unit that governed all of the Iberian peninsula south of the Pyrenees from 1580–1640 Thursday, 4 October 1582 was followed by Friday, 15 October 1582, with ten days "missing". Events 610 - Heraclius arrives by ship from Africa at Constantinople, overthrows Byzantine Emperor Phocas Events 533 - Byzantine General Belisarius makes his formal entry into Carthage, having conquered it from the Countries that did not change until the 1700s observed an additional leap year, necessitating eleven "missing days". A leap year (or intercalary year) is a year containing one or more extra days (or in the case of Lunisolar calendars an extra month in order to keep the Some countries did not change until the 1800s or 1900s, necessitating one or two more "missing days".
France changed from Julian to Gregorian Calendar on 9 December 1582 JU where the next day was 20 December 1582 GR. Early Modern France is the Early modern period of French history from the end of the 15th century to the end of the 18th century (or from the French Renaissance Events 536 - Byzantine General Belisarius enters Rome while the Ostrogothic garrison peacefully leaves the city Events 69 - Vespasian, formerly a general under Nero, enters Rome to claim the title of Emperor. France used the French Republican Calendar from 22 September 1792 GR to 31 December 1805 GR. The French Republican Calendar or French Revolutionary Calendar was a Calendar proposed during the French Revolution, and used by the French government Events 66 - Emperor Nero creates the Legion I Italica. 1236 - The Lithuanians Year 1792 ( MDCCXCII) was a Leap year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a Leap year Events 406 – Vandals, Alans and Suebians cross the Rhine, beginning an invasion of Gallia. Year 1805 ( MDCCCV) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar (or
In Russia, the terms "Old Style" and "New Style" have the same significance as elsewhere. The Russian Empire ( Pre-reform Russian: Pоссійская Имперія Modern Russian: Российская Империя translit: Rossiyskaya The start of the year was moved to January 1 in 1700, but the Gregorian calendar was introduced there much later, in the Russian SFSR—on February 14, 1918 (Gregorian calendar). New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Events 842 - Charles the Bald and Louis the German swear the Oaths of Strasbourg in the French and German Year 1918 ( MCMXVIII) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar (or a Common Hence the October Revolution of 1917 is so called, despite having started on November 7 under the Gregorian calendar (October 25 [Julian calendar]). The October Revolution (Октябрьская революция Oktyabrskaya revolyutsiya) also known as the Soviet Revolution Events 1492 - The Ensisheim Meteorite the oldest Meteorite with a known date of impact strikes the Earth around noon in a Wheat Events 1147 - The Portuguese, under Afonso I, and Crusaders from England and Flanders conquer Lisbon after a 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. The Encyclopædia Britannica is a general English-language encyclopaedia published by Encyclopædia Britannica Inc 
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. William Shakespeare ( baptised Miguel de Cervantes Saavedra ( in modern Spanish; September 29, 1547 &ndash April 22, 1616) was a Spanish Novelist Events 215 BC - A temple is built on the Capitoline Hill dedicated to Venus Erycina to commemorate the Roman defeat at  England was still using the Julian calendar in 1616, while Spain was using the Gregorian calendar. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. Cervantes actually died ten days before Shakespeare.
Occasionally using different calendars has caused confusion between contemporaries. For example 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. Napoleon Bonaparte (15 August 1769 – 5 May 1821 was a French military and political leader who had a significant impact on the History of Europe. The Battle of Austerlitz (Bitva u Slavkova also known as the Battle of the Three Emperors, was one of Napoleon's greatest victories effectively destroying the 
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. The Battle of Agincourt was an English victory against a larger French army in the Hundred Years' War. Events 1147 - The Portuguese, under Afonso I, and Crusaders from England and Flanders conquer Lisbon after a See also Crispin of Viterbo, Capuchin Franciscan Blessed Crispin and Crispinian are the Christian Patron saints of cobblers 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 533 - Byzantine General Belisarius makes his formal entry into Carthage, having conquered it from the Events 81 - Domitian becomes Emperor of the Roman Empire upon the death of his brother Titus. Year 1752 ( MDCCLII) was a Leap year starting on Saturday (link will display the full calendar for European countries but not Great Britain) of 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. The Battle of Blenheim (referred to in some countries as the Second Battle of Höchstädt) fought on 13 August 1704 was a major battle of the War of the Spanish Succession Events 3114 BC - According to the Lounsbury correlation the start of the Maya calendar. Year 1704 ( MDCCIV) was a Leap year starting on Tuesday (link will display the full calendar of the Gregorian calendar (or a 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). William III or William of Orange (14 November 1650 &ndash 8 March 1702 He is informally known in Northern Ireland and Scotland as "King Billy" Brixham (ˈbrɪksəm is a small town in the county of Devon, in the south-west of England. Events 1499 - Publication of the Catholicon in Treguier ( Brittany) The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands Events 308 - The Congress of Carnuntum: Attempting to keep peace within the Roman Empire, the leaders of the Tetrarchy declare
The Battle of Boyne took place only a few months later in Ireland on 1 July 1690 "Old Style". The Battle of the Boyne (Cath na Bóinne was a turning point in the Williamite claim on the English throne "July 1st" redirects here For the Ayumi Hamasaki song see H (song. However, it is commemorated as taking place on 12 July "New Style" by the Orange parades on "The Twelfth", possibly because of Protestant Orangemen's antipathy to Papal innovations and because it is in part a conflation of commemorations of the Battle of Aughrim, 12 July (OS) 1691. Events 1191 - Saladin 's garrison surrenders ending the two-year Siege of Acre. The Orange Institution, more commonly known as the Orange Order or the Orange Lodge, is a Protestant fraternal organisation based predominantly The Twelfth is an annual Protestant celebration on 12 July, originating in Ireland. Protestantism refers to the forms of Christian faith and practice that originated in the 16th century Protestant Reformation. The Battle of Aughrim was the decisive battle of the Williamite War in Ireland. Events 1191 - Saladin 's garrison surrenders ending the two-year Siege of Acre.
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. In historical materials dates will often be indicated with what appears to be duplicate or excessive digits sometimes separated by a hyphen or a slash John Dee (13 July 1527 – 1608 or 1609 was a noted English mathematician, astronomer, astrologer, geographer, occultist 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 'OS' or Old Style, the other 'NS' 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. Thomas Jefferson (April 13 1743 – July 4 1826 was the third President of the United States (1801–1809 the principal author of the Declaration of Independence  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 April 2 and his New Style birthday of April 13. Events 68 - Galba, Governor of Hispania, names himself legatus senatus populique Romani, breaking the line of Events 1111 - Henry V is crowned Holy Roman Emperor. 1204 - The Fourth Crusade sacks Constantinople 
Japan, Korea, and China started using the Gregorian calendar on 1 January of 1873, 1896, and 1912, respectively. The, or Meiji era, denotes the 45-year reign of the Meiji Emperor, running in the Gregorian calendar, from 23 October 1868 to 30 July The Korean Empire was a former small empire of Korea that lasted from the Gwangmu Restoration of 1897 until Japan 's annexation of Korea in 1910 China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Year 1873 ( MDCCCLXXIII) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common Year 1896 ( MDCCCXCVI) was a Leap year starting on Wednesday (link will display the full calendar of the Gregorian Calendar (or a Leap year Year 1912 ( MCMXII) was a Leap year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Leap year starting  They had used lunisolar calendars previously. A lunisolar calendar is a Calendar in many Cultures whose date indicates both the Moon phase and the time of the solar Year. 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. The arabic numerals (often capitalized are the ten Digits (0 1 2 3 4 5 6 7 8 9 which—along with the system
Japan started using the Gregorian calendar on 1 January 1873, locally known as "the first day of the first month of Meiji 6" (明治6年1月1日 Meiji rokunen ichigatsu tsuitachi?). New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Year 1873 ( MDCCCLXXIII) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common The preceding day, 31 December 1872, was "the second day of the twelfth month of Meiji 5" (明治5年12月2日 Meiji gonen jūnigatsu futsuka?). Events 406 – Vandals, Alans and Suebians cross the Rhine, beginning an invasion of Gallia. Year 1872 ( MDCCCLXXII) was a Leap year starting on Monday (link will display the full calendar of the Gregorian Calendar (or a Leap year
Japan currently employs two calendar systems: Gregorian and modified traditional nengō. The Japanese era calendar scheme is a common Calendar scheme used in Japan, which identifies a year by the combination of the and the year number within the era Specifically, the months and days now correspond to those of the Gregorian calendar, but the year is expressed as an offset of the era. The Japanese era calendar scheme is a common Calendar scheme used in Japan, which identifies a year by the combination of the and the year number within the era For example, the Gregorian year 2008 corresponds to Heisei 20. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common is the current era name in Japan. The Heisei era started on January 8, 1989, just one day after the death of the reigning Emperor Hirohito An era does not necessarily begin on January 1st.
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. New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Year 1896 ( MDCCCXCVI) was a Leap year starting on Wednesday (link will display the full calendar of the Gregorian Calendar (or a Leap year Not to be confused with Qin Dynasty, the first dynasty of Imperial China  The lunisolar Korean calendar is now used in very limited unofficial purposes only. The traditional Korean calendar is a Lunisolar calendar which like the traditional calendars of other East Asian countries was based on the Chinese calendar
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. REPUBLIC OF CHINA ARTICLE GUIDELINES New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Year 1912 ( MCMXII) was a Leap year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Leap year starting The Chinese calendar is lunisolar, incorporating elements of a Lunar calendar with those of a Solar calendar. The reference has been a longitude of 120°E since 1929, which is also used for Chinese Standard Time (UTC+8). China standard time or Beijing time is the Time zone observed in the People's Republic of China ( PRC) UTC+8 is a band of Timezones separated from the Greenwich Mean Time by 8 hours 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. Hong Kong ( officially the Hong Kong Special Administrative Region, is a territory located on China 's south coast on the Pearl River Delta, and borders For a topic outline on this subject see List of basic Macau topics. For the biogeographical region see Malesia Malaysia (məˈleɪʒə or /məˈleɪziə/ is a country that consists of thirteen states and The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. Singapore Taiwan ( Taiwanese: Tâi-oân/Tāi-oân (historically 大灣/台員/大員/台圓/大圓/台窩灣 is an Island in East Asia. Chinese New Year is the most important of the Traditional Chinese holidays.
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. A Chinese character, also known as a Han character ( is a Logogram used in writing Chinese (hanzi Japanese (
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 CE. The Republic of China calendar (民國紀元 is the method of numbering years currently used in the Republic of China ( Taiwan, Penghu, Kinmen