question: If the Earth doesn't take exactly 24h were all the leftover minutes go?
comment: What you have just discovered is the difference between a sidereal day and a solar day. A sidereal day is the length of time the Earth takes to rotate as measured against a very distant star. A solar day is the length of time it takes the Earth to rotate so that the same part of the Earth is pointing directly at the sun. What you are missing is that while the Earth is rotating it is also moving around the sun. So, the time for it to complete one rotation is slightly less than 24 hours, but during that time the Earth also moved a little around the sun. So, it takes a little longer for the sun to be at its highest point in the sky. So, one day isn't actually how long it takes for the planet to spin, it is the time it takes for the sun to be in the same position in the sky. Here's a good video on the topic: URL_0
passages: Occasionally, in years when Holy Saturday falls on the last Saturday of March, Earth Hour is moved a week early rather than its traditional date.
  
  Earth Hour 2020 is scheduled for March 28, from 8:30 pm to 9:30 pm.
  
  Section::::History.
  
  Section::::History.:Conception and start: 2004–2007.
   BULLET::::- In March 2010, "The Daily Telegraph" quoted Ross Hayman, head of media relations at the UK National Grid, as saying "it could therefore result in an increase in carbon emissions" due to complications related to rapidly lowering then raising electricity generation.
   March 1986 and January 1987: The problem of the rubber bushings on the quarter bell chimes freezing recurred, muffling the chimes.
  
  30 April 1997: The clock stopped 24 hours before the general election, and stopped again three weeks later.
  
  Section::::Clock.:Breakdowns and other incidents.:21st century.
  
  27 May 2005: The clock stopped at 10:07 pm, possibly because of hot weather; temperatures in London had reached an unseasonable 31.8 °C (90 °F). It resumed, but stopped again at 10:20 pm, and remained still for about 90 minutes before resuming.
   Earth Hour is supported around the world by UNESCO, the UN Environment Programme, the International Trade Union Confederation, Woodland, CBRE Group, the National Hockey League, FIFA, UEFA, Hilton Worldwide, Girl Scouts of the US, World Organization of the Scout Movement, HSBC, World Association of the Girl Guides and Girl Scouts, Philips, IKEA, The Body Shop, ING Vysya Bank, and more.
  
  Section::::Measurement of reduction in electricity use.
  
  The Earth Hour Global FAQ page states:
   Earth Hour 2016 was on Saturday, March 19, from 8:30 p.m. to 9:30 p.m. during participants' local time. It was also changed to avoid coinciding with the Christian Holy Saturday, which fell on March 26 of that year. It was the 10th anniversary of the campaign's beginnings in Sydney, Australia. Östersund in Sweden cancelled the 2016 event, following a spate of sex attacks, highlighting safety as a subject for discussion when saving resources. Almost all the countries in the world observed Earth Hour.
  
  Section::::History.:2017.
  
  Earth Hour occurred on Saturday, March 25.
  
  Section::::History.:2018.
   Earth Hour 2015 took place on Saturday, March 28, again between 8:30 and 9:30 p.m. local time. The tagline for the global campaign was "Change Climate Change", returning to the movement's original focus to initiate citizen action on global warming. A day before the event, over 170 countries and territories had confirmed their participation; with more than 1200 landmarks and close to 40 UNESCO world heritage sites set for the switch off.
   BULLET::::- Seventy dials provide 122 indications. These include the seconds, hours, days and years. The clock is a perpetual one that can register up to 10,000 years, including adjustments for leap year cycles. The clock also indicates the times of sunrise and sunset.
  
  BULLET::::- Twenty-one automated figures either ring the quarter-hour and the hour, or perform the Resurrection of Christ at noon, and his burial at 3 pm.
   Earth Hour 2013 was held across the world on Saturday, March 23 at 8:30 p.m. to 9:30 p.m. local time to avoid taking place after European Summer Time began, ensuring a greater impact for the lights-off event. It was also changed to avoid coinciding with the Christian Holy Saturday, which fell on March 30 of that year.
  
  Section::::History.:2013.:Africa.
  
  In 2013, the world's first Earth Hour Forest began in Uganda, an ongoing project that aims to restore 2700 hectares of degraded land. Standard Chartered Bank-Uganda pledged to help fill the forest with more than 250,000 trees.
   Bjørn Lomborg, author of "The Skeptical Environmentalist", wrote, "It is vital to make solar and other new technology cheaper than fossil fuels quickly so we can turn off carbon energy sources for a lot longer than one hour and keep the planet running... Fossil fuels literally gave us an enlightenment, by lighting our world and giving us protection from the fury of the elements. It is ironic that today's pure symbolism should hark back to a darker age." Lomborg also pointed out the feel-good factor Earth Hour creates, noting that it is an "ineffective feel good event" that makes people feel they are doing something for the environment, while in reality the amount of carbon emissions reduced by the earth hour is negligible.
   At the cemetery, Gaspar tells Billy the story of how a pope from the 16th century decreed that the entire civilized world adopt a new calendar, which advanced time by thirteen days. Billy speculates that the observance of equinoxes and solstices probably had to do with improved scientific knowledge in those days. Gaspar agrees, but adds the pope's calculations were off by one hour. That hour "slipped free and bounced through eternity". It is an hour that must never be used, and must never toll. To do so would bring eternal night when the pocket watch tolls midnight.
   According to a Zogby International online survey, 36 million Americans—approximately 16 percent of the United States adult population—participated in Earth Hour 2008. The survey also showed there was a 4 percentage point increase in the level of interest in environmental issues such as climate change and pollution directly after the event (73 percent pre-event versus 77 percent post-event).
  
  Tel Aviv scheduled their Earth Hour for Thursday March 27, 2008 to avoid conflict with Sabbath. Dublin moved their Earth Hour to between 9 and 10 p.m. due to their northern geographical location.
   Considering that sundial time varies +- 15 minutes throughout the year, the Cotehele clock was a perfect instrument for measuring time in the 15th and 16th century. If run 24 hours a day (the strike can be turned off at night), it only needed adjusting every couple of days at noon with the help of a sundial whenever the sun was out. Even if the sun wasn't visible for a longer stretch of days, the clock would still keep good enough time if it was wound fully once per day.
  
  Section::::References.
   A 2014 study published in "Energy Research and Social Science" compiled 274 measurements of observed changes in electricity demand caused by Earth Hour in 10 countries, spanning 6 years, and found that the events reduced electricity consumption an average of 4%. The study noted the policy challenge of converting Earth Hour's short-term energy saving into longer-term actions, including sustained changes in behaviour and investment.
  
  Section::::Criticism.
   The shortest time spans occur twice each year, around 25 March (24 hours minus 18 seconds) and 13 September (24 hours minus 22 seconds).
  
  Section::::Nomenclature.
  
  In the US, noon is commonly indicated by 12 p.m., and midnight by 12 a.m. While some argue that such usage is "improper" based on the Latin meaning (a.m. stands for "ante meridiem" and p.m. for "post meridiem", meaning "before midday" and "after midday" respectively), digital clocks are unable to display anything else, and an arbitrary decision must be made. 
   In 2004, confronted with scientific findings, WWF Australia met with advertising agency Leo Burnett Sydney to "discuss ideas for engaging Australians on the issue of climate change". The idea of a large scale switch off was coined and developed in 2006, originally under the working title "The Big Flick". WWF Australia presented their concept to Fairfax Media who, along with Sydney Lord Mayor Clover Moore, agreed to back the event. The 2007 Earth Hour was held on March 31 in Sydney, Australia at 7:30 pm, local time.
   Ireland, as a whole, had a reduction in electricity use of about 1.5% for the evening. In the three-hour period between 6:30 p.m. and 9:30 pm, there was a reduction of 50 megawatts, saving 150 megawatt-hours, or approximately 60 tonnes of carbon dioxide.
  
  In Dubai, where external lighting on several major city landmarks was turned off and street lighting in selected areas was dimmed by 50%, the Electricity and Water Authority reported savings of 100 megawatt-hours of electricity. This represented a 2.4% reduction in demand compared to before the hour began.
   Section::::Description.:Times after 24:00.
  
  Time-of-day notations beyond 24:00 (such as 24:01 or 25:00 instead of 00:01 or 01:00) are not commonly used and not covered by the relevant standards. However, they have been used occasionally in some special contexts in the United Kingdom, Canada, Japan, South Korea, Hong Kong and China where business hours extend beyond midnight, such as broadcast television production and scheduling.
  
  Section::::Description.:Computer support.
   Some cities and landmarks took the opportunity to make more long-term adjustments to their everyday power consumption. In Chicago, the Building Owners and Managers Association (BOMA) developed lighting guidelines to reduce light pollution and reduce the carbon footprint of downtown buildings. Mount Rushmore in South Dakota started powering down each night around 9 p.m. instead of 11 p.m.
  
  In Vietnam, electricity demand fell 500,000 kWh during Earth Hour 2010, which was three times larger than the first time the country joined the event in 2009.
   BULLET::::- Greenwich Mean Time (GMT) or Coordinated Universal Time (UTC) is designated time zone Z, and thus called "Zulu time". (When used as a modern time zone, in practice, GMT and UTC coincide. For other purposes there may be a difference of about a second.)
  
  BULLET::::- Hours are always "hundred", never "thousand"; 1000 is "ten hundred" not "one thousand"; 2000 is "twenty hundred" not "two thousand".
  
  Section::::History.
   Section::::History.
   BULLET::::- In regions of extremely high latitude where the duration of days and nights vary considerably, the times of the fast are fixed by the clock.
  
  Section::::Laws concerning fasting.:Exemptions from fasting.
   BULLET::::- Expressing sarcastic support for Earth Hour, the pro-carbon Carbon Sense Coalition wants Earth Hour to be renamed "Blackout Night", and to be held outside on the shortest and coldest day of the year "...to prepare our population for the dark days ahead".
   The UTC time standard, which is widely used for international timekeeping and as the reference for civil time in most countries, uses the international system (SI) definition of the second. The UTC second has been calibrated with atomic clocks to the duration of the Earth's mean day of the astronomical year 1900. Because the rotation of the Earth has since slowed down, the duration of today's mean solar day is longer (by roughly 0.001 seconds) than 24 SI hours ( SI seconds). UTC would step ahead of solar time and need adjustment even if the Earth's rotation remained constant in the future. Therefore, if the UTC day were defined as precisely SI seconds, the UTC time-of-day would slowly drift apart from that of solar-based standards, such as Greenwich Mean Time (GMT) and its successor UT1. The point on the Earth's equator where the sun culminates at 12:00:00 UTC would wander to the East by some 300 m each year. The leap second compensates for this drift, by occasionally scheduling a UTC day with or (in principle) SI seconds.
   In the Philippines, 1,067 towns and cities pledged participation in 2010 and over 15 million Filipinos participated in the event.
  
  About 4000 cities participated, including landmarks such as Big Ben, the Empire State Building, the Sydney Opera House, the Eiffel Tower, the Parthenon, the Brandenburg Gate, and the Forbidden City.
  
  Section::::History.:2011.
   Earth Hour 2018 took place on March 24, from 8:30 p.m. to 9:30 p.m. in participants' time, in order to avoid coinciding with Christian Holy Saturday which fell on March 31.
  
  Section::::History.:2019.
  
  Earth Hour 2019 was held on March 30, from 8:30 p.m. to 9:30 pm. Miss Earth 2018 Nguyễn Phương Khánh from Vietnam was designated as the Earth Hour Ambassador to implement several environmental protection activities. As ambassador, Phuong Khanh urged everyone to voluntarily turn off unnecessary lights and equipment for an hour, contributing to spreading the message "Save Energy, Save Earth - Energy saving, Earth protection".
  
  Section::::Organizations that support Earth Hour.
  
presuppositions: Days are measured one way.
corrections: Days are measure as sidereal days and solar days.
raw_presuppositions: Days are measured one way. Leftover minutes go somewhere.
raw_corrections: Days are measure as sidereal days and solar days. This is the difference between a solar day and a sidereal day.