The World Clock — Worldwide (2024)

FAQs

Where is the official clock of the world? ›

NIST-F1 is a cesium fountain clock, a type of atomic clock, in the National Institute of Standards and Technology (NIST) in Boulder, Colorado, and serves as the United States' primary time and frequency standard.

International Atomic Time is an extraordinarily precise means of time-keeping. Atomic clocks deviate only 1 second in up to 100 million years.

Present-Day Master Clocks

A modern atomic version of a master clock can be found at the U.S. Naval Observatory. Maintained by the USNO Time Service Department, it's used by a large portion of the world's communications, scientific and financial infrastructure to ensure accuracy.

03:14:38 P.M.

The International Earth Rotation and Reference Systems Service (IERS) measure Earth time, known as Universal Time, by watching the stars race past as the planet spins. They then combine this with International Atomic Time to get a final figure for Coordinated Universal Time.

Using ultra-cold strontium atoms and powerful laser beams, the team at the University of Science and Technology of China created a clock with stability and uncertainty under 5 quintillionths. The achievement makes China only the second country in the world after the US to achieve such precise timekeeping.

In 1947, artist and Bulletin member Martyl Langsdorf created the iconic Doomsday Clock to signal how close humanity was to self-destruction. Today, the Doomsday Clock is located at the Bulletin offices in the Keller Center, home to the University of Chicago Harris School of Public Policy.

Physicists have built the most accurate clock ever: one that gains or loses only one second every 40 billion years¹. Alexander Aeppli at the research institute JILA in Boulder, Colorado, and his collaborators suspended 40,000 strontium atoms in a vacuum using a pattern of standing light waves.

TAI is computed by the International Bureau of Weights and Measures (BIPM) located near Paris, France. Coordinated Universal Time (UTC) is based on TAI, but it is adjusted by leap seconds to account for the difference between the definition of the second and the rotation of Earth.

USNO Master Clock

The DoD common time reference is the U.S. Naval Observatory Master Clock. It is generated at USNO in Washington, D.C. and at the Alternate Master Clock Facility at Schriever Space Force Base in Colorado.

Does the world have a Doomsday Clock? ›

Reflecting international events dangerous to humankind, the Clock has been adjusted 25 times since its inception in 1947, when it was set to "seven minutes to midnight". The Doomsday Clock has become a universally recognized metaphor according to The Two-Way, an NPR blog.

Sir Sanford Fleming, who worked as an engineer for Canadian railways, knew this problem firsthand when he missed a train in 1876. This experience gave him the idea for a standard time, with hourly variations according to different zones around the world.

In short, nothing has changed for daylight saving time (DST) in 2022. Daylight saving time will end at 2 a.m local time on Nov. 6. People in states that observe it will move their clocks back one hour.

Prior to 1972, this time was called Greenwich Mean Time (GMT) but is now referred to as Coordinated Universal Time or Universal Time Coordinated (UTC). It is a coordinated time scale, maintained by the Bureau International des Poids et Mesures (BIPM). It is also known as "Z time" or "Zulu Time".

Daylight saving time will begin for 2024 on Sunday, March 10 at 2 a.m. local time, when our clocks will move forward an hour, part of the twice-annual time change that affects most, but not all, Americans.

UTC is the universal standard time coordinated through international agreement.

The usage of UTC and GMT is based upon a twenty four hour clock, similar to military time, and is based upon the 0° longitude meridian, referred to as the Greenwich meridian in Greenwich, England.

USNO Master Clock

The DoD common time reference is the U.S. Naval Observatory Master Clock. It is generated at USNO in Washington, D.C. and at the Alternate Master Clock Facility at Schriever Space Force Base in Colorado.

The Doomsday Clock is placed in the bulletin offices at the University of Chicago.