Archiv: Zeitrechnung / time calculation


05.07.2026 - 23:13 [ Wikipedia ]

Leap second

A leap second (sometimes called intercalary second)[1] is a one-second adjustment occasionally applied to Coordinated Universal Time (UTC), to accommodate the difference between International Atomic Time (TAI), as measured precisely by atomic clocks, and observed solar time (UT1), which varies due to irregularities and long-term slowdown in the Earth‘s rotation.

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After 1972, both clocks have been ticking in SI seconds, so the difference between their displays at any time is 10 seconds plus the total number of leap seconds that have been applied to UTC as of that time; as of 2024, 27 leap seconds have been applied to UTC, so the difference is 10 + 27 = 37 seconds. The most recent leap second was on December 31, 2016.

05.07.2026 - 23:09 [ Wikipedia ]

Schaltsekunde

Die Erde rotiert minimal langsamer, als bei der Definition der Sekunde zugrunde gelegt wurde; ein tatsächlicher mittlerer Sonnentag dauert daher um Sekundenbruchteile länger als 86.400 Sekunden.

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Im Jahr 1972 betrug die Differenz zwischen UTC und TAI vor EinfĂĽhrung der Schaltsekunde bereits 10 Sekunden, heute liegt sie bei 37 Sekunden.

05.07.2026 - 23:01 [ Forbes.com ]

Earth’s Rotation Is Slowing Faster Than In 3.6 Million Years

(June 7, 2026)

Earth’s rotation is gradually slowing as climate change melts glaciers and polar ice sheets, redistributing water across the planet and subtly lengthening the day. According to new research from the University of Vienna and ETH Zürich, the current increase in day length — 1.33 milliseconds per century — is unprecedented over at least the past 3.6 million years. It’s a new measure of how profoundly human-driven warming is affecting the Earth system, even as only 48% of Americans believe climate change is the result of human activity.

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Researchers reconstructed changes in day length over the past 3.6 million years using fossil remains of benthic foraminifera — single-celled marine microorganisms on the seafloor — and advanced machine-learning techniques.

10.08.2021 - 13:08 [ International Earth Rotation and Reference Systems Service - iers.org ]

Measuring the irregularities of the Earth‘s rotation

The variability of the earth-rotation vector relative to the body of the planet or in inertial space is caused by the gravitational torque exerted by the Moon, Sun and planets, displacements of matter in different parts of the planet and other excitation mechanisms.

15.09.2020 - 18:00 [ CNN ]

In Earth‘s early history, a day was 23.5 hours and a year lasted 372 days

(13.03.2020)

We‘ve long known that an Earth day lasts 24 hours, and that remains constant because Earth‘s trip around the sun doesn‘t vary.

However, the number of days that make an Earth year have shifted and shortened because days have grown longer. That is thanks to the moon‘s gravity, which draws on ocean‘s tides and slows Earth‘s rate of rotation.

15.09.2020 - 18:00 [ Frankfurter Allgemeine Zeitung ]

Eine Schaltsekunde mehr Zeit

(30.12.2008)

Wie unregelmäßig sich die Erde dreht, sieht man daran, dass zwischen 1999 und 2006 sieben Jahre vergehen mussten, bis eine Schaltsekunde nötig wurde; diesmal sind es nur drei Jahre.

15.09.2020 - 17:10 [ CBS News ]

On-Time Earth Baffles Scientists

(31. März 2003)

To make the world’s official time agree with where the Earth actually is in space, scientists in 1972 started adding an extra „leap second“ on the last day of the year.

For 28 years, scientists repeated the procedure. But in 1999, they discovered the Earth was no longer lagging behind.

At the National Institute for Science and Technology in Boulder, spokesman Fred McGehan said most scientists agree the Earth’s orbit around the sun has been gradually slowing for millennia. But he said they don’t have a good explanation for why it’s suddenly on schedule.

13.03.2020 - 08:50 [ CBS News ]

On-Time Earth Baffles Scientists

(31. März 2003)

To make the world’s official time agree with where the Earth actually is in space, scientists in 1972 started adding an extra „leap second“ on the last day of the year.

For 28 years, scientists repeated the procedure. But in 1999, they discovered the Earth was no longer lagging behind.

At the National Institute for Science and Technology in Boulder, spokesman Fred McGehan said most scientists agree the Earth’s orbit around the sun has been gradually slowing for millennia. But he said they don’t have a good explanation for why it’s suddenly on schedule.

13.03.2020 - 08:41 [ CNN ]

In Earth‘s early history, a day was 23.5 hours and a year lasted 372 days

(today)

We‘ve long known that an Earth day lasts 24 hours, and that remains constant because Earth‘s trip around the sun doesn‘t vary.