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 (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 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 congnates 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.
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 prior to the change.
Category:Calendar
Category:Terminology