{"id":764,"date":"2006-02-26T21:30:00","date_gmt":"2006-02-26T21:30:00","guid":{"rendered":"http:\/\/informacyde.com\/blog\/?p=764"},"modified":"2008-08-08T16:47:14","modified_gmt":"2008-08-08T14:47:14","slug":"histoire-du-calendrier","status":"publish","type":"post","link":"https:\/\/www.informacyde.com\/blog\/divers\/histoire-du-calendrier\/","title":{"rendered":"Histoire du calendrier"},"content":{"rendered":"

Pourquoi 365 jours ? Pourquoi 28 jours en f\u00e9vrier et 29 tous les 4 ans ? Tels sont les questions que je me suis pos\u00e9… sans savoir pourquoi ! J’ai trouv\u00e9 une r\u00e9ponse sur ce site<\/a>, la voici :<\/p>\n

\n

Les principes fondamentaux de notre calendrier ont \u00e9t\u00e9 \u00e9labor\u00e9s bien avant J\u00e9sus Christ et reposent sur l’ann\u00e9e solaire. Le probl\u00e8me qui se pose et que vous connaissez bien (normalement) c’est que la Terre ne met pas un nombre de jours exact pour tourner autour du soleil : ellet met 365 jours 5 heures 49 minutes (365,2422 jours).<\/p>\n

Une ann\u00e9e de 365 jours est trop courte de pratiquement un quart de jour. Au bout de quatre ans notre calendrier est donc en avance d’une journ\u00e9e par rapport \u00e0 la r\u00e9volution de la Terre autour du soleil.<\/p>\n

Les civilisations anciennes ont pendant longtemps pratiqu\u00e9 l’ann\u00e9e de 365 jours, voire 360 jours pour certaines. Des jours \u00e9taient rajout\u00e9s par-ci par-l\u00e0 selon le bon vouloir des pr\u00eatres ou des politiciens. C’est le grand Jules (Jules C\u00e9sar) qui, pour mettre fin au d\u00e9sordre qui r\u00e9gnait \u00e0 Rome, est \u00e0 l’origine de la r\u00e9forme la plus importante de notre syst\u00e8me calendaire.<\/p>\n

Sur les conseils d’un astronome Grec vachement intelligent, Sosig\u00e8ne, Jules d\u00e9cida que tous les quatre ans l’ann\u00e9e comporterait 366 jours au lieu de 365. A l’\u00e9poque ce jour fut ajout\u00e9 au mois de F\u00e9vrier par le doublement du 24\u00e8me jour (pour des raisons dr\u00f4lement compliqu\u00e9es que F\u00e9vrier c’\u00e9tait d\u00e9j\u00e0 un mois de 28 jours que donc c’\u00e9tait le mieux pour en rajouter un mais que comme c’\u00e9tait un mois d\u00e9di\u00e9 aux dieux mauvais et que les mois avec des jours impairs \u00e9taient d\u00e9di\u00e9s aux dieux gentils alors on pouvait pas faire un mois de F\u00e9vrier de 29 jours et que donc pour faire comme si on changeait rien on aurait dit qu’il valait mieux qu’un autre jour ait lieu 2 fois, … Respirez !). Le 24 F\u00e9vrier \u00e9tant, dans la d\u00e9finition romaine, le sixi\u00e8me jour avant les calendes de Mars son double devenait le \u00ab\u00a0second sixi\u00e8me jour avant les calendes de Mars\u00a0\u00bb. Ce qui se dit, pour ceux qui comme moi ont appris le latin dans Ast\u00e9rix et Ob\u00e9lix : \u00ab\u00a0bis-sextus ante calendas martias\u00a0\u00bb dont il nous est rest\u00e9 le terme \u00ab\u00a0bissextile\u00a0\u00bb.<\/p>\n

Il fut \u00e9galement d\u00e9cid\u00e9 que l’\u00e9quinoxe de printemps (point de rep\u00e8re privil\u00e9gi\u00e9 parmi les \u00e9v\u00e8nements c\u00e9lestes) co\u00efnciderait avec le 25 Mars de chaque ann\u00e9e. Pour ce faire l’ann\u00e9e 708 de Rome, ann\u00e9e de la r\u00e9forme, fut allong\u00e9e de 90 jours. Enfin, le commencement de l’ann\u00e9e fut ramen\u00e9 du 1er Mars au 1er Janvier.<\/p>\n

Le calendrier mis en place par Jules C\u00e9sar (calendrier julien) a perdur\u00e9 pendant plus de 15 si\u00e8cles. Pourtant, il fallut le r\u00e9former. Apr\u00e9s plusieurs si\u00e8cles d’utilisation il \u00e9tait \u00e0 nouveau d\u00e9cal\u00e9 de plusieurs jours par rapport au soleil.<\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"

Pourquoi 365 jours ? Pourquoi 28 jours en f\u00e9vrier et 29 tous les 4 ans ? Tels sont les questions que je me suis pos\u00e9… sans savoir pourquoi ! J’ai trouv\u00e9 une r\u00e9ponse…<\/p>\n","protected":false},"author":10,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[8],"tags":[],"class_list":["post-764","post","type-post","status-publish","format-standard","hentry","category-divers"],"yoast_head":"\nHistoire du calendrier - Informacyde<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.informacyde.com\/blog\/divers\/histoire-du-calendrier\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Histoire du calendrier - Informacyde\" \/>\n<meta property=\"og:description\" content=\"Pourquoi 365 jours ? 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