{"id":6,"date":"2018-04-10T12:07:09","date_gmt":"2018-04-10T12:07:09","guid":{"rendered":"http:\/\/robinfo.oma.be\/?page_id=6"},"modified":"2026-03-19T13:56:51","modified_gmt":"2026-03-19T12:56:51","slug":"home","status":"publish","type":"page","link":"https:\/\/robinfo.oma.be\/en\/","title":{"rendered":"Home"},"content":{"rendered":"<p>[vc_row][vc_column][vc_column_text]<\/p>\n<h1 style=\"text-align: center;\">Daylight saving time<\/h1>\n<p style=\"text-align: center; font-size: large;\">On Sunday, <strong style=\"color: red;\">March 29, 2026<\/strong>, we switch from winter time to <strong>summer time<\/strong>.<br \/>\nAt 2:00 in the morning we add one hour to the clock (to 3:00).<\/p>\n<p>[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column width=&#8221;1\/2&#8243;]<div class=\"porto-ultimate-content-box-container \"><div class=\"porto-ultimate-content-box\" style=\"\" id=\"porto_ucb_7224\"><style>#porto-info-list181226514769d28f34da6f0 i { color: #0088cc;font-size: 50px; }<\/style><ul id=\"porto-info-list181226514769d28f34da6f0\" class=\"porto-info-list \"><li class=\"porto-info-list-item\"><i class=\"porto-info-icon far fa-calendar-alt\"><\/i><div class=\"porto-info-list-item-desc\">\n<h2>Ephemeris per year<\/h2>\n<p>Mentions the days and hours of several astronomical events on the site for a given year, concerning the Sun, the Moon, the calendar, the eclipses&#8230; <a href=\"https:\/\/robinfo.oma.be\/en\/ephemeris\/\">More information&#8230;<\/a><\/div><\/li><li class=\"porto-info-list-item\"><i class=\"porto-info-icon far fa-dot-circle\"><\/i><div class=\"porto-info-list-item-desc\">\n<h2>The eclipses<\/h2>\n<p>All information on solar and lunar eclipses, (partially) visible or not in Belgium for a given year. <a href=\"https:\/\/robinfo.oma.be\/en\/astro-info\/eclipses\/\">More information&#8230;<\/a><\/div><\/li><\/ul><\/div><\/div>[\/vc_column][vc_column width=&#8221;1\/2&#8243;]<div class=\"porto-ultimate-content-box-container \"><div class=\"porto-ultimate-content-box\" style=\"\" id=\"porto_ucb_5343\"><style>#porto-info-list8215255369d28f34da916 i { color: #0088cc;font-size: 50px; }<\/style><ul id=\"porto-info-list8215255369d28f34da916\" class=\"porto-info-list \"><li class=\"porto-info-list-item\"><i class=\"porto-info-icon fas fa-sun\"><\/i><div class=\"porto-info-list-item-desc\">\n<h2>The Sun<\/h2>\n<p>All the information on sunrise and sunset, beginning of the astronomical seasons, lengthening and shortening of the day duration&#8230; for a given year. <a href=\"https:\/\/robinfo.oma.be\/en\/astro-info\/sun\/\">More information&#8230;<\/a><\/div><\/li><li class=\"porto-info-list-item\"><i class=\"porto-info-icon fas fa-moon\"><\/i><div class=\"porto-info-list-item-desc\">\n<h2>The Moon<\/h2>\n<p>All the information on moonrise and sunset as well as the lunar phases for a given year. <a href=\"https:\/\/robinfo.oma.be\/en\/astro-info\/moon\/\">More information&#8230;<\/a><\/div><\/li><\/ul><\/div><\/div>[\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n<h2>Who we are<\/h2>\n<p>As an intermediate between the Observatory and the public, the Communication and Information Service aims to communicate and promote the Observatory&#8217;s research activities and heritage, and also to provide and relay scientific information to the public.<\/p>\n<p>The activities of the Communication and Information Service consist of several parts:<\/p>\n<ul>\n<li>Information to the public about astronomy and astronomy-related matters<\/li>\n<li>Answers to questions and inquiries from the public, the press and the authorities<\/li>\n<li>Help in all kind of outreach (exhibitions, events as the Open Doors) and public relations activities (press communications, press conferences etc.)<\/li>\n<li>Collaboration with the Planetarium, notably for the permanent exhibitions at the Heysel site<\/li>\n<li>Publication and edition of the <a href=\"https:\/\/www.astro.oma.be\/en\/information\/publications\/annual-reports\/\" target=\"_blank\" rel=\"noopener noreferrer\">annual report<\/a> and of <a href=\"https:\/\/www.astro.oma.be\/en\/information\/publications\/\" target=\"_blank\" rel=\"noopener noreferrer\">the Yearbook of the Royal Observatory of Belgium<\/a><\/li>\n<li>Preparation of texts for printing or of <a href=\"http:\/\/(http:\/\/www.astro.oma.be\/en\/news\/\" target=\"_blank\" rel=\"noopener noreferrer\">news for the web site<\/a><\/li>\n<li>Management of the archives, the museum and the library<\/li>\n<\/ul>\n<p>[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column]<div class=\"porto-faqs porto-faqs4rpy wpb_content_element \"><h4 class=\"wpb_heading \"><\/p>\n<h2>Frequently asked questions<\/h2>\n<p><\/h4>\r\n\t<div class=\"page-faqs clearfix m-t-lg wpb_custom_7fe7ddf8f1a240d6488c8a8c41279112\" id=\"porto_faqs_aob7\">\r\n\r\n\t\t\r\n\t\t\r\n\t\t<div class=\"faq-row faqs-container\">\r\n\t\t\t\n<article class=\"faq miscellaneous post-4502 type-faq status-publish hentry faq_cat-miscellaneous\">\n\t<section class=\"toggle\">\n\t\t<label>What is a meteorite and how can you recognize one?<\/label>\n\t\t<div class=\"toggle-content\">\n\t\t<span class=\"entry-title\" style=\"display: none;\">What is a meteorite and how can you recognize one?<\/span><span class=\"vcard\" style=\"display: none;\"><span class=\"fn\"><a href=\"https:\/\/robinfo.oma.be\/en\/author\/florevm\/\" title=\"Posts by Flore Van Maldeghem\" rel=\"author\">Flore Van Maldeghem<\/a><\/span><\/span><span class=\"updated\" style=\"display:none\">2025-11-03T09:18:20+01:00<\/span><p class=\"western\">A meteorite is a piece of rock from space that enters the atmosphere. It does not burn up (like a <a href=\"https:\/\/robinfo.oma.be\/en\/faq\/what-is-een-shooting-star-meteor\/\">meteor<\/a>) and reaches the surface of the Earth. It is quite rare to find a meteorite, especially in an urban environment.<\/p>\r\n<p class=\"western\" align=\"justify\">There are different kinds of meteorites, but there are some general characteristics that can help to decide if the rock is a meteorite.<\/p>\r\n\r\n<ul>\r\n \t<li>\r\n<p class=\"western\" align=\"justify\">Meteorites are magnetic: they won\u2019t stick on a fridge themselves, but a magnet will stick to the meteorite.<\/p>\r\n<\/li>\r\n \t<li>\r\n<p class=\"western\" align=\"justify\">The rock seems burned on the outside. A meteorite has a rounded shape and brown rusty, to black color because of the heat during atmospheric entry.<\/p>\r\n<\/li>\r\n \t<li>\r\n<p class=\"western\" align=\"justify\">You will not see holes or pores at the surface of a meteorite. Sometimes you can see shiny or rusty patches of iron.<\/p>\r\n<\/li>\r\n \t<li>\r\n<p class=\"western\" align=\"justify\">A meteorite will feel heavier compared to a rock from earth of the same size.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<p class=\"western\">The Royal Observatory of Belgium <b>does not<\/b> identify or collect meteorites. If you think you found a meteorite, you can use the document below to verify. Still convinced it is a meteorite? Contact <span style=\"color: #467886;\"><u><a href=\"mailto:tleduc@naturalsciences.be\">tleduc@naturalsciences.be<\/a><\/u><\/span> from the Royal Belgian Institute for Natural Sciences. Add some pictures (with scale) and a description (location, exterior, weight, volume, magnetism, \u2026) from the rock. This will make identification easier.<\/p>\r\n<a href=\"https:\/\/robinfo.oma.be\/wp-content\/uploads\/2025\/11\/Meteowrong-EN.pdf\">Meteorite or meteowrong?<\/a>\t\t<\/div>\n\t<\/section>\n<\/article>\n\n<article class=\"faq seasons post-2510 type-faq status-publish hentry faq_cat-seasons\">\n\t<section class=\"toggle\">\n\t\t<label>Why does the day of the equinox have (slightly) more than 12 hours of daylight?<\/label>\n\t\t<div class=\"toggle-content\">\n\t\t<span class=\"entry-title\" style=\"display: none;\">Why does the day of the equinox have (slightly) more than 12 hours of daylight?<\/span><span class=\"vcard\" style=\"display: none;\"><span class=\"fn\"><a href=\"https:\/\/robinfo.oma.be\/en\/author\/lbspham\/\" title=\"Posts by Le Binh San Pham\" rel=\"author\">Le Binh San Pham<\/a><\/span><\/span><span class=\"updated\" style=\"display:none\">2020-03-23T11:43:46+01:00<\/span>The equinox is defined as the moment at which the plane of the Earth equator passes through the centre of the Sun. In other words, it is the moment at which the center of the visible Sun is directly above the equator. The northern and southern hemispheres of the Earth are then illuminated in the same way. This moment occurs two times each year: around 20 March (spring equinox) and 23 September (autumnal equinox).\r\n\r\nHowever, during the equinox, the day and the night are not of equal length. Actually, the length of the day is slightly longer than the length of the night.\r\n\r\nWhy is this the case? This is mainly for two reasons:\r\n<ul>\r\n \t<li>The Sun is not perceived from the Earth as a point but as a luminous disc. Sunrise (sunset) is defined as the time when the upper edge of the solar disc, not the centre of the Sun, appears (disappears) on the horizon. Therefore, since the upper edge of the Sun appears before its centre, and disappears after its centre, we gain a few minutes of sunlight during the equinox.<\/li>\r\n \t<li>Sunlight is deflected by the atmosphere. This is due to atmospheric refraction, a phenomena that \u201cflattens\u201d the Sun near the horizon. As a result, the upper edge of the Sun may be visible when it is actually below the horizon.<\/li>\r\n<\/ul>\r\n<figure id=\"attachment_2511\" aria-describedby=\"caption-attachment-2511\" style=\"width: 900px\" class=\"wp-caption aligncenter\"><img class=\"size-large wp-image-2511\" src=\"https:\/\/robinfo.oma.be\/wp-content\/uploads\/2020\/03\/zonsondergang-1024x731.jpg\" alt=\"Illustration of the Sun refraction\" width=\"900\" height=\"642\" \/><figcaption id=\"caption-attachment-2511\" class=\"wp-caption-text\">Illustration of the Sun refraction phenomena.<\/figcaption><\/figure>\r\n\r\nThese two effects combined therefore explain why the length of the day is longer than 12 hours on the day of the equinox. The day during which the length of the day is closest to 12 hours is before the spring equinox and after the autumnal equinox. In Belgium, this day is the 17th or 18th of March and the 25th or 26th of September.\t\t<\/div>\n\t<\/section>\n<\/article>\n\n<article class=\"faq time-and-calendar post-336 type-faq status-publish hentry faq_cat-time-and-calendar\">\n\t<section class=\"toggle\">\n\t\t<label>Why does the Easter date in 2019 fall on April 21 but not on March 24?<\/label>\n\t\t<div class=\"toggle-content\">\n\t\t<span class=\"entry-title\" style=\"display: none;\">Why does the Easter date in 2019 fall on April 21 but not on March 24?<\/span><span class=\"vcard\" style=\"display: none;\"><span class=\"fn\"><a href=\"https:\/\/robinfo.oma.be\/en\/author\/lbspham\/\" title=\"Posts by Le Binh San Pham\" rel=\"author\">Le Binh San Pham<\/a><\/span><\/span><span class=\"updated\" style=\"display:none\">2025-02-25T15:29:41+01:00<\/span>The (Catholic) Easter date was fixed by the Council of Nicea in 325 AD. The rule is as follows: Easter is the first Sunday after the first full moon of spring.\r\n\r\nTaking into account modern astronomical calculations, in 2019,\r\n<ul>\r\n \t<li>spring begins on March 20 at 22:58 (universal time);<\/li>\r\n \t<li>the first full moon that follows takes place on March 21 at 2:43 (universal time).<\/li>\r\n<\/ul>\r\nTherefore, Easter would fall on the first Sunday following, i.e. on March 24, 2019.\r\n\r\nHowever, the Easter date in 2019 is April 21.\r\n\r\nThe reason why the two dates do not coincide is that the authorities of the Catholic Church do not want to depend on astronomers. For this reason, they have introduced the following simplifications into their calculations:\r\n\r\n<strong>1) Early spring (in the northern hemisphere):<\/strong>\r\n\r\nIn astronomy, it coincides with the vernal equinox, the moment when the terrestrial equatorial plane crosses the centre of the Sun and the Earth's North Pole emerges from its winter night. The equinox date fluctuates in the calendar, in part because the Earth's period of revolution around the Sun is 365.2422 days instead of 365-366 calendar days (other factors influence the calculation of the spring date, but their influence is too small to be mentioned here). As a result, early spring is between March 19 and 21. The church has decided to set the date from spring to March 21.\r\n\r\n<strong>2) The dates of the full moon:<\/strong>\r\n\r\nIt is not easy to determine the exact orbit of the Moon and the corresponding lunar phases. In the 5th century BC, the Greek Meton of Athens found an elegant solution to simplify this problem. After a number of observations he concluded that the Sun and Moon are in the same relative position with respect to the Earth after 235 lunar months, or 19 years. This cycle has become the basis for the calculation of the full moon in the Catholic Church. In 1582, this rule was adapted to the new Gregorian calendar, our current calendar.\r\n\r\nThe rule for calculating the Easter date therefore remains valid, but we must also take into account the two simplifications mentioned above. In other words,\r\n<ul>\r\n \t<li>spring begins on March 21;<\/li>\r\n \t<li>the first full moon after March 21, 2019 (according to Meton calculations) takes place on April 20, 2019.<\/li>\r\n<\/ul>\r\nTherefore, Easter falls on the Sunday following this full moon, i.e. on April 21, 2019.\r\n\r\nIn addition to 2019, there are other years when the \"ecclesiastical\" Easter date does not correspond to the \"astronomical\" Easter date.\r\n\r\nIn the thousand years following 1582, the year of the Gregorian calendar reform, there were 84 such occurrences. The previous date was in 1981, the next will be in 2038.\r\n\r\nThe German mathematician Carl Friedrich Gauss published in 1800 a mathematical algorithm to calculate the Easter date for a given year. He uses different terms of the comput such as the golden number or the epacte. This algorithm is still used today, sometimes in a simplified version.\r\n\r\n<strong>Links:<\/strong>\r\n<a href=\"https:\/\/robinfo.oma.be\/astro-info\/calendar\/easter-dates-from-1583-to-3000\/\" target=\"_blank\" rel=\"noopener\">Easter dates from 1583 to 3000<\/a>\r\n<a href=\"https:\/\/robinfo.oma.be\/astro-info\/calendar\/algorithm-for-the-computation-of-the-easter-date\/\" target=\"_blank\" rel=\"noopener\">Algorithm for the computation of the Easter date<\/a>\t\t<\/div>\n\t<\/section>\n<\/article>\n\n<article class=\"faq time-and-calendar post-296 type-faq status-publish hentry faq_cat-time-and-calendar\">\n\t<section class=\"toggle\">\n\t\t<label>Questions about Christian, Islamic, Jewish calendars&#8230;<\/label>\n\t\t<div class=\"toggle-content\">\n\t\t<span class=\"entry-title\" style=\"display: none;\">Questions about Christian, Islamic, Jewish calendars&#8230;<\/span><span class=\"vcard\" style=\"display: none;\"><span class=\"fn\"><a href=\"https:\/\/robinfo.oma.be\/en\/author\/lbspham\/\" title=\"Posts by Le Binh San Pham\" rel=\"author\">Le Binh San Pham<\/a><\/span><\/span><span class=\"updated\" style=\"display:none\">2019-03-08T11:46:59+01:00<\/span>Since 2018, we no longer give information on religious calendars. We now only give information on the Belgian civil calendar, which is based on the Gregorian calendar.\t\t<\/div>\n\t<\/section>\n<\/article>\n\n<article class=\"faq time-and-calendar post-282 type-faq status-publish hentry faq_cat-time-and-calendar\">\n\t<section class=\"toggle\">\n\t\t<label>What is the Gregorian Calendar Reform?<\/label>\n\t\t<div class=\"toggle-content\">\n\t\t<span class=\"entry-title\" style=\"display: none;\">What is the Gregorian Calendar Reform?<\/span><span class=\"vcard\" style=\"display: none;\"><span class=\"fn\"><a href=\"https:\/\/robinfo.oma.be\/en\/author\/lbspham\/\" title=\"Posts by Le Binh San Pham\" rel=\"author\">Le Binh San Pham<\/a><\/span><\/span><span class=\"updated\" style=\"display:none\">2019-03-04T19:25:12+01:00<\/span>The length of the year in the Western calendar has its origin in the Roman calendar. Since 46 BC, Julius Caesar wanted to establish 365-day years with a leap year every 4 years. However, it will take some time before the Julian calendar is properly applied.\r\n\r\nThe scope of this calendar refers to the length of the tropical year. This is the time it takes for the Sun to return to the same position in the sky. During this time, the Sun moves from its northernmost position to its southernmost position relative to the equator and vice versa. This results in the frequency of the seasons that the calendar wants to reflect.\r\n\r\nA tropical year lasts 365.242190 days or 365 days 5 hours 48 minutes 45.2 seconds, so it is not an integer number of days. A good approximation was made by introducing a year of 366 days every 4 years as already provided for in the Julian calendar. This gives a year with an average duration of 365.25 days.\r\n\r\nOver time, a small difference (0.0078 days per year) began to be a problem. Thus, because of the imperfection of the Julian calendar, spring in the 16th century was moved to March 11. In order to put everything in order, Pope Gregory XIII decided in 1582 that October 4 should be followed by October 15. In addition, at the request of the astronomers of the time, he implemented the following new rule: a year divisible by 100 will not be leapfrogging, unless it is a multiple of 400. the first rule alone produces an average year of 365.24 days every 100 years. The second rule is to get very close to the tropical year, i.e. 365.2425 days every 400 years. It is only after 3000 years that the inaccuracy deviates by one day.\r\n\r\nHowever, this timetable was not immediately adopted by all countries. Russia waited until 1917, which is why the October revolution is now commemorated in November. Sweden became so confused in the 18th century that it was necessary to give 30 days in February in 1712. Greece adopted the Gregorian calendar in 1923.\r\n\r\nSeveral people noted that some sources contradict each other. Thus, the southern regions of present-day Belgium moved to the Gregorian calendar from 1582 to 1583. In some places (Flanders and Hainaut) Christmas Day was not celebrated in 1582, since December 21, 1582 was immediately followed by January 1, 1583. Even if Brabant and Zeeland had made the transition earlier (14-25 December), it was not without difficulties. The Liege \u00e9chevinage introduced the Gregorian reform in February 1583.\r\n\r\nYou can find more information about calendars on, for example, <a href=\"https:\/\/www.tondering.dk\/claus\/calendar.html\" target=\"_blank\" rel=\"noopener\">The Calender FAQ<\/a>.\t\t<\/div>\n\t<\/section>\n<\/article>\n\n<article class=\"faq time-and-calendar post-229 type-faq status-publish hentry faq_cat-time-and-calendar\">\n\t<section class=\"toggle\">\n\t\t<label>When does a new century of millenium begin?<\/label>\n\t\t<div class=\"toggle-content\">\n\t\t<span class=\"entry-title\" style=\"display: none;\">When does a new century of millenium begin?<\/span><span class=\"vcard\" style=\"display: none;\"><span class=\"fn\"><a href=\"https:\/\/robinfo.oma.be\/en\/author\/lbspham\/\" title=\"Posts by Le Binh San Pham\" rel=\"author\">Le Binh San Pham<\/a><\/span><\/span><span class=\"updated\" style=\"display:none\">2019-03-04T16:35:17+01:00<\/span>A full century is 100 years old. 100 years must therefore <strong>pass<\/strong> before a new century can begin. Since our era begins with the year 1 AD, the 1st century ended with the end of the year 100. Thus, the year 1900 had to end first before the 19<sup>th<\/sup> century could be finished. The 20<sup>th<\/sup> century also lasted 100 years and ended with the beginning of 2001.\r\n\r\nThe reasoning is the same for a millennium. A millennium lasts 1000 years. The second millennium began on 1 January 1001 and ended on 31 December 2000.\r\n\r\nEach era begins with year 1. T<strong>here is no such thing as year 0<\/strong>.\r\n<h3>A brief historical overview<\/h3>\r\nAmong the Romans, who laid the foundations of our calendar, the era began with the foundation of Rome, fixed in 753 BC (Ab Urbe condita or AUC). However, there were other starting dates. Since the 3<sup>rd<\/sup> century AD, the years have been calculated from the ascent of the Emperor Diocletian. Since he persecuted Christians, this time was called the era of the martyrs.\r\n\r\nIn the 6<sup>th<\/sup> century, the monk Dionysius Exiguus (Dionysius the Little) began to count from the year that, according to him, was the year of Christ's birth. Thus, 248 Anno Diocletiani was in fact the year 532 AD. According to Dionysius, Jesus Christ was born on December 25 of the year before year 1, he did not know the number zero, but there is no era in which a year 0 would be placed.\r\n\r\nIn the 8th century, the English Father Bede the Venerable also began to count the years before Christ. The year 1 BC was therefore just before the year 1 AD. The year 1 BC was therefore the last year of the 1st century BC.\r\n\r\nIt should be noted that this Christian way of counting years was used by the Church in the Middle Ages and much later in the civil world. There were many other ways to count. There were controversies about the date of the beginning and in particular about the year of Christ's birth and Herod's death in 4 BC, which should be brought forward by a few years, to around 6 or 7 BC.\r\n\r\nYou can find more information about calendars on <a href=\"https:\/\/www.tondering.dk\/claus\/calendar.html\" target=\"_blank\" rel=\"noopener\">The Calender FAQ<\/a> web page.\t\t<\/div>\n\t<\/section>\n<\/article>\n\n<article class=\"faq miscellaneous post-223 type-faq status-publish hentry faq_cat-miscellaneous\">\n\t<section class=\"toggle\">\n\t\t<label>Questions about weather and climate<\/label>\n\t\t<div class=\"toggle-content\">\n\t\t<span class=\"entry-title\" style=\"display: none;\">Questions about weather and climate<\/span><span class=\"vcard\" style=\"display: none;\"><span class=\"fn\"><a href=\"https:\/\/robinfo.oma.be\/en\/author\/lbspham\/\" title=\"Posts by Le Binh San Pham\" rel=\"author\">Le Binh San Pham<\/a><\/span><\/span><span class=\"updated\" style=\"display:none\">2025-02-26T16:01:05+01:00<\/span>If you have questions about weather or climate, you can consult the web pages of the <a href=\"https:\/\/www.meteo.be\/en\/brussels\" target=\"_blank\" rel=\"noopener\">Royal Meteorological Institute<\/a> (KMI-IRM).\t\t<\/div>\n\t<\/section>\n<\/article>\n\n<article class=\"faq miscellaneous post-219 type-faq status-publish hentry faq_cat-miscellaneous\">\n\t<section class=\"toggle\">\n\t\t<label>Questions about tides<\/label>\n\t\t<div class=\"toggle-content\">\n\t\t<span class=\"entry-title\" style=\"display: none;\">Questions about tides<\/span><span class=\"vcard\" style=\"display: none;\"><span class=\"fn\"><a href=\"https:\/\/robinfo.oma.be\/en\/author\/lbspham\/\" title=\"Posts by Le Binh San Pham\" rel=\"author\">Le Binh San Pham<\/a><\/span><\/span><span class=\"updated\" style=\"display:none\">2025-02-26T16:00:59+01:00<\/span>If you are looking for concrete information about sea tides on the Belgian coast and on the inland rivers, please contact the Ministry of the Flemish Community, Afdeling Kust - Vlaamse Hydrografie, Vrijhavenstraat 3, 8400 Oostende (059\/554211) and\/or Afdeling Maritieme Schelde, Tavernierkaai 3, 2000 Antwerpen (03\/2220803). Some websites also provide information about this, e.g. <a href=\"http:\/\/www.vlaamsehydrografie.be\" target=\"_blank\" rel=\"noopener\">http:\/\/www.vlaamsehydrografie.be<\/a> or <a href=\"http:\/\/www.lin.vlaanderen.be\/awz\" target=\"_blank\" rel=\"noopener\">http:\/\/www.lin.vlaanderen.be\/awz<\/a> that gives all water levels.\r\n\r\nAt the Royal Observatory the earth tides are measured and studied using gravimeters. The small differences between the astronomical calculations (position sun, earth, moon) and the gravimetric measurements are investigated in detail to detect any other external influences. More information: <a href=\"https:\/\/www.astro.oma.be\/en\/scientific-research\/seismology\/\" target=\"_blank\" rel=\"noopener\">https:\/\/www.astro.oma.be\/en\/scientific-research\/seismology\/<\/a>.\t\t<\/div>\n\t<\/section>\n<\/article>\n\t\t<\/div>\r\n\r\n\t\t\r\n\t<\/div>\r\n\r\n\t\r\n\t<\/div>[\/vc_column][\/vc_row]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>[vc_row][vc_column][vc_column_text] Daylight saving time On Sunday, March 29, 2026, we switch from winter time to summer time. At 2:00 in the morning we add one hour to the clock (to 3:00). [\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column width=&#8221;1\/2&#8243;][\/vc_column][vc_column width=&#8221;1\/2&#8243;][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text] Who we are As an intermediate between the Observatory and the public, the Communication and Information Service aims to communicate and [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/pages\/6"}],"collection":[{"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/comments?post=6"}],"version-history":[{"count":17,"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/pages\/6\/revisions"}],"predecessor-version":[{"id":4648,"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/pages\/6\/revisions\/4648"}],"wp:attachment":[{"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/media?parent=6"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}