{"id":51853,"date":"2026-11-01T09:16:21","date_gmt":"2026-11-01T09:16:21","guid":{"rendered":"https:\/\/www.worldclock.com\/siderisk-tid-kalkulator\/"},"modified":"2026-11-01T09:16:21","modified_gmt":"2026-11-01T09:16:21","slug":"siderisk-tid-kalkulator","status":"publish","type":"page","link":"https:\/\/www.worldclock.com\/no\/siderisk-tid-kalkulator\/","title":{"rendered":"Kalkulator for siderisk tid og juliansk dato"},"content":{"rendered":"<div class=\"wc wc-tool-page wc-tool-page--sidereal\"><header class=\"wc-thero\"><div class=\"wc-thero__text\"><nav class=\"wc-crumbs\" aria-label=\"Breadcrumb\"><ol><li><a href=\"https:\/\/www.worldclock.com\/no\/\">Verdensklokke<\/a><\/li><li><a href=\"https:\/\/www.worldclock.com\/no\/verktoy\/\">Tidsverkt\u00f8y<\/a><\/li><li><span aria-current=\"page\">Kalkulator for siderisk tid og juliansk dato<\/span><\/li><\/ol><\/nav><p class=\"wc-eyebrow\"><span aria-hidden=\"true\">\ud83c\udf0c<\/span> Gratis verkt\u00f8y<\/p><h1 class=\"wc-thero__title\">Kalkulator for siderisk tid og juliansk dato<\/h1><p class=\"wc-thero__lead\">Live lokal siderisk tid, siderisk tid i Greenwich, juliansk dato og modifisert juliansk dato for ethvert sted og tidspunkt.<\/p><\/div><\/header><div class=\"wc-tool\"><div class=\"wc-sid\" data-wc-tool=\"sidereal\" data-default=\"{&quot;n&quot;:&quot;Greenwich&quot;,&quot;t&quot;:&quot;Europe\\\/London&quot;,&quot;f&quot;:&quot;gb&quot;,&quot;a&quot;:51.4769,&quot;o&quot;:-0.0005}\"><div class=\"wc-tbar\"><div class=\"wc-field wc-field--grow\"><span>Sted<\/span><div class=\"wc-search wc-search--tool\" data-wc-search data-mode=\"add\"><input type=\"search\" placeholder=\"S\u00f8k etter en by \u2026\" aria-label=\"S\u00f8k etter en by \u2026\" autocomplete=\"off\"><ul class=\"wc-search__results\" hidden><\/ul><\/div><\/div><label class=\"wc-field\"><span>Lengdegrad \u00b0<\/span><input type=\"number\" step=\"0.0001\" min=\"-180\" max=\"180\" data-lng><\/label><button type=\"button\" class=\"wc-btn wc-btn--ghost\" data-geo>\ud83d\udccd Bruk min posisjon<\/button><\/div><div class=\"wc-sunc__place\" data-place><\/div><div class=\"wc-sunc__cards\" data-cards><\/div><div class=\"wc-panel\" style=\"margin-top:16px\"><h2>Regn om en dato<\/h2><label class=\"wc-field\"><span>Dato og klokkeslett (UTC)<\/span><input type=\"datetime-local\" step=\"1\" data-dt><\/label><dl class=\"wc-unix__out\" data-out><\/dl><\/div><\/div><\/div><section class=\"wc-section wc-tool-info\"><div class=\"wc-prose\"><h2>Hva er siderisk tid (stjernetid)?<\/h2><p>Siderisk tid m\u00e5ler jordas rotasjon i forhold til de fjerne stjernene i stedet for solen. Et siderisk d\u00f8gn er omtrent <strong>23 timer 56 minutter 4 sekunder<\/strong> \u2013 nesten fire minutter kortere enn et sold\u00f8gn \u2013 s\u00e5 stjernene st\u00e5r opp fire minutter tidligere hver natt. Astronomer bruker <strong>lokal siderisk tid (LST)<\/strong> til \u00e5 rette teleskoper: en stjerne st\u00e5r h\u00f8yest p\u00e5 himmelen n\u00e5r LST er lik dens rektascensjon.<\/p><p><strong>Juliansk dato<\/strong> er en sammenhengende telling av dager siden kl. 12 UTC 1. januar 4713 f.Kr., som brukes for \u00e5 unng\u00e5 kalenderkomplikasjoner i astronomien. <strong>Modifisert juliansk dato<\/strong> (MJD) er JD \u2212 2 400 000,5 og starter ved midnatt.<\/p><\/div><\/section><section class=\"wc-section wc-faq\"><h2>Ofte stilte sp\u00f8rsm\u00e5l<\/h2><details><summary>Hvordan regner jeg ut lokal siderisk tid?<\/summary><p>Regn ut Greenwich middelsiderisk tid ut fra den julianske datoen, og legg deretter til lengdegraden din i timer (lengdegrad \u00f7 15, \u00f8st positiv). Kalkulatoren over gj\u00f8r dette live for ethvert sted.<\/p><\/details><\/section><section class=\"wc-section wc-tools-grid\"><div class=\"wc-section__head\"><h2>Flere gratis tidsverkt\u00f8y<\/h2><a href=\"https:\/\/www.worldclock.com\/no\/verktoy\/\">Alle verkt\u00f8y \u2192<\/a><\/div><div class=\"wc-toolcards\"><a class=\"wc-toolcard wc-toolcard--sun\" href=\"https:\/\/www.worldclock.com\/no\/soloppgang-solnedgang\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83c\udf05<\/span><span class=\"wc-toolcard__name\">Soloppgang og solnedgang<\/span><span class=\"wc-toolcard__desc\">Soloppgang, solnedgang og gyllen time.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--golden\" href=\"https:\/\/www.worldclock.com\/no\/gyllen-time-kalkulator\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83d\udcf8<\/span><span class=\"wc-toolcard__name\">Kalkulator for gyllen time<\/span><span class=\"wc-toolcard__desc\">Beste lys for bilder.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--moon\" href=\"https:\/\/www.worldclock.com\/no\/manefase\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83c\udf15<\/span><span class=\"wc-toolcard__name\">M\u00e5nefase i dag<\/span><span class=\"wc-toolcard__desc\">Kveldens m\u00e5ne og m\u00e5nekalender.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--fullmoon\" href=\"https:\/\/www.worldclock.com\/no\/fullmanekalender\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83c\udf1d<\/span><span class=\"wc-toolcard__name\">Fullm\u00e5nekalender<\/span><span class=\"wc-toolcard__desc\">Datoer og navn for fullm\u00e5ner.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--moonrise\" href=\"https:\/\/www.worldclock.com\/no\/maneoppgang-manenedgang\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83c\udf19<\/span><span class=\"wc-toolcard__name\">Tider for m\u00e5neoppgang og m\u00e5nenedgang<\/span><span class=\"wc-toolcard__desc\">N\u00e5r m\u00e5nen st\u00e5r opp og g\u00e5r ned.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--birthmoon\" href=\"https:\/\/www.worldclock.com\/no\/manefase-bursdag\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83c\udf82<\/span><span class=\"wc-toolcard__name\">M\u00e5nen p\u00e5 bursdagen din<\/span><span class=\"wc-toolcard__desc\">M\u00e5nen p\u00e5 en hvilken som helst dato.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--astro\" href=\"https:\/\/www.worldclock.com\/no\/astronomisk-kalender\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83d\udd2d<\/span><span class=\"wc-toolcard__name\">Astronomisk kalender<\/span><span class=\"wc-toolcard__desc\">Form\u00f8rkelser, meteorer og himmelfenomener.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--converter\" href=\"https:\/\/www.worldclock.com\/no\/tidssonekonverter\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83d\udd01<\/span><span class=\"wc-toolcard__name\">Tidssonekonverter<\/span><span class=\"wc-toolcard__desc\">Regn om et klokkeslett mellom alle byer.<\/span><\/a><\/div><\/section><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","footnotes":"","bs_cache_bypass_cache":0,"bs_cache_related_page":0},"class_list":["post-51853","page","type-page","status-publish","hentry"],"acf":[],"taxonomy_info":[],"featured_image_src_large":false,"author_info":{"display_name":"clocker","author_link":"https:\/\/www.worldclock.com\/no\/author\/clocker\/"},"comment_info":"","_links":{"self":[{"href":"https:\/\/www.worldclock.com\/no\/wp-json\/wp\/v2\/pages\/51853","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.worldclock.com\/no\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.worldclock.com\/no\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.worldclock.com\/no\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.worldclock.com\/no\/wp-json\/wp\/v2\/comments?post=51853"}],"version-history":[{"count":0,"href":"https:\/\/www.worldclock.com\/no\/wp-json\/wp\/v2\/pages\/51853\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.worldclock.com\/no\/wp-json\/wp\/v2\/media?parent=51853"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}