{"id":51663,"date":"2026-11-01T09:13:42","date_gmt":"2026-11-01T09:13:42","guid":{"rendered":"https:\/\/www.worldclock.com\/stjernetid-beregner\/"},"modified":"2026-11-01T09:13:42","modified_gmt":"2026-11-01T09:13:42","slug":"stjernetid-beregner","status":"publish","type":"page","link":"https:\/\/www.worldclock.com\/da\/stjernetid-beregner\/","title":{"rendered":"Beregner for stjernetid &#038; 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\/da\/\">Verdensur<\/a><\/li><li><a href=\"https:\/\/www.worldclock.com\/da\/vaerktoejer\/\">Tidsv\u00e6rkt\u00f8jer<\/a><\/li><li><span aria-current=\"page\">Beregner for stjernetid &amp; juliansk dato<\/span><\/li><\/ol><\/nav><p class=\"wc-eyebrow\"><span aria-hidden=\"true\">\ud83c\udf0c<\/span> Gratis v\u00e6rkt\u00f8j<\/p><h1 class=\"wc-thero__title\">Beregner for stjernetid &amp; juliansk dato<\/h1><p class=\"wc-thero__lead\">Live lokal stjernetid, Greenwich-stjernetid, juliansk dato og modificeret 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\u00f8g efter en by\u2026\" aria-label=\"S\u00f8g efter en by\u2026\" autocomplete=\"off\"><ul class=\"wc-search__results\" hidden><\/ul><\/div><\/div><label class=\"wc-field\"><span>L\u00e6ngdegrad \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 Brug min placering<\/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>Omregn en dato<\/h2><label class=\"wc-field\"><span>Dato &amp; tid (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>Hvad er stjernetid?<\/h2><p>Stjernetid m\u00e5ler Jordens rotation i forhold til de fjerne stjerner i stedet for solen. Et stjerned\u00f8gn er cirka <strong>23 timer 56 minutter og 4 sekunder<\/strong> \u2013 n\u00e6sten fire minutter kortere end et sold\u00f8gn \u2013 s\u00e5 stjernerne st\u00e5r op fire minutter tidligere hver nat. Astronomer bruger <strong>lokal stjernetid (LST)<\/strong> til at rette teleskoper ind: En stjerne st\u00e5r h\u00f8jest p\u00e5 himlen, n\u00e5r LST svarer til dens rektascension.<\/p><p><strong>Juliansk dato<\/strong> er en fortl\u00f8bende opt\u00e6lling af dage siden kl. 12 UTC den 1. januar 4713 f.Kr. og bruges til at undg\u00e5 kalenderkomplikationer i astronomien. <strong>Modificeret juliansk dato<\/strong> (MJD) er JD \u2212 2.400.000,5 og begynder ved midnat.<\/p><\/div><\/section><section class=\"wc-section wc-faq\"><h2>Ofte stillede sp\u00f8rgsm\u00e5l<\/h2><details><summary>Hvordan beregner jeg lokal stjernetid?<\/summary><p>Beregn Greenwich-middelstjernetid ud fra den julianske dato, og l\u00e6g s\u00e5 din l\u00e6ngdegrad i timer til (l\u00e6ngdegrad \u00f7 15, \u00f8st positiv). Beregneren ovenfor g\u00f8r det live for ethvert sted.<\/p><\/details><\/section><section class=\"wc-section wc-tools-grid\"><div class=\"wc-section__head\"><h2>Flere gratis tidsv\u00e6rkt\u00f8jer<\/h2><a href=\"https:\/\/www.worldclock.com\/da\/vaerktoejer\/\">Alle v\u00e6rkt\u00f8jer \u2192<\/a><\/div><div class=\"wc-toolcards\"><a class=\"wc-toolcard wc-toolcard--sun\" href=\"https:\/\/www.worldclock.com\/da\/solopgang-solnedgang\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83c\udf05<\/span><span class=\"wc-toolcard__name\">Solopgang &amp; solnedgang \u2013 beregner<\/span><span class=\"wc-toolcard__desc\">Solopgang, solnedgang og gyldne time.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--golden\" href=\"https:\/\/www.worldclock.com\/da\/gylden-time-beregner\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83d\udcf8<\/span><span class=\"wc-toolcard__name\">Beregner til gylden time<\/span><span class=\"wc-toolcard__desc\">Bedste lys til fotos.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--moon\" href=\"https:\/\/www.worldclock.com\/da\/maanefase\/\"><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\">Nattens m\u00e5ne &amp; m\u00e5nekalender.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--fullmoon\" href=\"https:\/\/www.worldclock.com\/da\/fuldmaanekalender\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83c\udf1d<\/span><span class=\"wc-toolcard__name\">Fuldm\u00e5nekalender<\/span><span class=\"wc-toolcard__desc\">Datoer &amp; navne for fuldm\u00e5ner.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--moonrise\" href=\"https:\/\/www.worldclock.com\/da\/maaneopgang-maanenedgang\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83c\udf19<\/span><span class=\"wc-toolcard__name\">M\u00e5neopgang &amp; m\u00e5nenedgang<\/span><span class=\"wc-toolcard__desc\">Hvorn\u00e5r m\u00e5nen st\u00e5r op &amp; g\u00e5r ned.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--birthmoon\" href=\"https:\/\/www.worldclock.com\/da\/maanefase-foedselsdag\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83c\udf82<\/span><span class=\"wc-toolcard__name\">M\u00e5nen p\u00e5 din f\u00f8dselsdag<\/span><span class=\"wc-toolcard__desc\">M\u00e5nen p\u00e5 enhver dato.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--astro\" href=\"https:\/\/www.worldclock.com\/da\/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 &amp; himmelf\u00e6nomener.<\/span><\/a><a class=\"wc-toolcard wc-toolcard--converter\" href=\"https:\/\/www.worldclock.com\/da\/tidszoneomregner\/\"><span class=\"wc-toolcard__icon\" aria-hidden=\"true\">\ud83d\udd01<\/span><span class=\"wc-toolcard__name\">Tidszoneomregner<\/span><span class=\"wc-toolcard__desc\">Omregn et tidspunkt mellem 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-51663","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\/da\/author\/clocker\/"},"comment_info":"","_links":{"self":[{"href":"https:\/\/www.worldclock.com\/da\/wp-json\/wp\/v2\/pages\/51663","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.worldclock.com\/da\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.worldclock.com\/da\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.worldclock.com\/da\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.worldclock.com\/da\/wp-json\/wp\/v2\/comments?post=51663"}],"version-history":[{"count":0,"href":"https:\/\/www.worldclock.com\/da\/wp-json\/wp\/v2\/pages\/51663\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.worldclock.com\/da\/wp-json\/wp\/v2\/media?parent=51663"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}