| Title: | Julian period |
| Original Title: | Période julienne |
| Volume and Page: | Vol. 12 (1765), p. 361 |
| Author: | Jean Le Rond d'Alembert (attributed) (biography) |
| Translator: | Philip Stewart [Duke University] |
| Original Version (ARTFL): | Link |
| Rights/Permissions: |
This text is protected by copyright and may be linked to without seeking permission. Please see http://quod.lib.umich.edu/d/did/terms.html for information on reproduction. |
| URL: | http://hdl.handle.net/2027/spo.did2222.0004.168 |
| Citation (MLA): | d'Alembert, Jean Le Rond (attributed). "Julian period." The Encyclopedia of Diderot & d'Alembert Collaborative Translation Project. Translated by Philip Stewart. Ann Arbor: Michigan Publishing, University of Michigan Library, 2021. Web. [fill in today's date in the form 18 Apr. 2009 and remove square brackets]. <http://hdl.handle.net/2027/spo.did2222.0004.168>. Trans. of "Période julienne," Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers, vol. 12. Paris, 1765. |
| Citation (Chicago): | d'Alembert, Jean Le Rond (attributed). "Julian period." The Encyclopedia of Diderot & d'Alembert Collaborative Translation Project. Translated by Philip Stewart. Ann Arbor: Michigan Publishing, University of Michigan Library, 2021. http://hdl.handle.net/2027/spo.did2222.0004.168 (accessed [fill in today's date in the form April 18, 2009 and remove square brackets]). Originally published as "Période julienne," Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers, 12:361 (Paris, 1765). |
JULIAN PERIOD is a sequence of 7980 years which comes from the multiplication of the cycles of the sun, the moon, and the indictions by one another, in other words, the numbers 28, 19, and 15. It begins on the first of January of the Julian year.
Each year of the Julian period has its solar cycle, its lunar cycle, and its particular indiction cycle, so that in the entire length of this period there are no two years which have at same time the same solar cycle, the same lunar cycle, and the same indiction cycle: whence it follows that all the years of the Julian period are distinguished from one another.
This period was invented by Scaliger as including all the epochs, to facilitate the reduction of the years of one given epoch to those of another similarly given epoch. [1] It accords with the Constantinopolitan epoch or period which was in use among the Greeks, with the difference that the solar and lunar cycles, and the indiction cycle, are counted differently, and that the first year of the Julian period differs from that of the Constantinopolitan period.
1. The reference is to the French scholar Joseph Juste Scaliger (1540-1609), author of De emendatione temporum (Paris, 1583).