Template:J2G

The following documentation is located at Template:J2G/documentation. ^[edit]

Useful links: subpage list • links • redirects • transclusions • errors (parser/module) • sandbox

Usage

This template converts a Julian calendar date to a date in the Gregorian calendar. It can be used, for example, to display the Gregorian date of a work that is dated according to the Julian calendar in a quotation template.

In Britain and the British Empire (including the eastern part of what is now the United States), the Gregorian calendar was adopted with effect from 3 September 1752 (Julian calendar) or 14 September 1752 (Gregorian). Thus, it is most likely unnecessary to use this template for dates of works published from that date onwards. For the years when other territories adopted the calendar, see "w:Gregorian calendar#Adoption" and "w:Adoption of the Gregorian calendar".

The template takes only one parameter: |1= or |date=, which is the Julian calendar date to be converted.

To determine the number of days that a Gregorian date is ahead of a Julian date, called the "secular difference" between the two calendars, the template uses the following formula:

D=\left\lfloor {Y/100}\right\rfloor -\left\lfloor {Y/400}\right\rfloor -2

In the formula, $D$ is the secular difference and $Y$ is the year using astronomical year numbering. $\left\lfloor {x}\right\rfloor$ means that if the result of the division is not an integer it is rounded down to the nearest integer. See "w:Gregorian calendar#Difference between Gregorian and Julian calendar dates".

Examples

Wikitext:
- {{J2G|date=2 September 1666}} (start of the Great Fire of London); or
- {{J2G|2 September 1666}}
Result: 12 September 1666

Wikitext: {{quote-book|en|chapter=The Tryal of the Conspirators Concern’d in the [[w:Gunpowder Plot|Gunpowder-Plot]], on Monday the 27th of January, Anno 1605. [[[Julian calendar]]] and in the Third Year of King James the First, in Westminster-Hall, before the Lords Commissioners there; [...]|editor=[[w:Thomas Salmon (historian)|[Thomas Salmon]]]|title=A Compleat Collection of State-Tryals, and Proceedings upon Impeachment for High Treason, and Other Crimes and Misdemeanours; {{...|From the Reign of King Henry the Fourth, to the End of the Reign of Queen Anne.}} In Four Volumes|location=London|publisher=Printed for Timothy Goodwin,{{nb...|against St. Dunstan’s Church in Fleet-Street}}; John Walthoe{{nb...|in the Middle-Temple Cloysters}}; Benj[amin] Tooke{{nb...|at the Middle-Temple Gate in Fleet-Street}}; John Darby{{nb...|in Bartholomew-Close}}; [[w:Jacob Tonson|Jacob Tonson]]{{nb...|against Katherine-Street in the Strand}}; and John Walthoe Jun.{{nb...|against the Royal-Exchange in Cornhill.}}|date={{J2G|27 January 1605}}|year_published=1719|volume=I|page=193|pageurl=https://archive.org/details/compleatcollecti01salmuoft/page/193/mode/1up|column=1|oclc=470588883|passage=But in the high Court of Parliament, every Man '''by virtue of''' the King's Authority, by Writ under the Great Seal, hath a judicial Place; and ſo conſequently the killing of every of them had been a ſeveral Treaſon, and ''Crimen [[lese majesty|læſæ Majeſtatis]]''.}}
Result:
- 1605 February 6, “The Tryal of the Conspirators Concern’d in the Gunpowder-Plot, on Monday the 27th of January, Anno 1605. [Julian calendar] and in the Third Year of King James the First, in Westminster-Hall, before the Lords Commissioners there; [...]”, in [Thomas Salmon], editor, A Compleat Collection of State-Tryals, and Proceedings upon Impeachment for High Treason, and Other Crimes and Misdemeanours; […] In Four Volumes, volume I, London: Printed for Timothy Goodwin, […]; John Walthoe […]; Benj[amin] Tooke […]; John Darby […]; Jacob Tonson […]; and John Walthoe Jun. […], published 1719, →OCLC, page 193, column 1:
  But in the high Court of Parliament, every Man by virtue of the King's Authority, by Writ under the Great Seal, hath a judicial Place; and ſo conſequently the killing of every of them had been a ſeveral Treaſon, and Crimen læſæ Majeſtatis.
Comment: The trial was held on 27 January 1605 according to the Julian calendar. By using {{J2G}}, the quotation template is directed to display the Gregorian calendar date (6 February 1603) as the date of the work.