# What is the Time with seconds

What's the time in seconds?

Modify time zones, view a second time zone, and learn how Outlook saves meetings that span multiple time zones. The UTC is often casually exchanged with the Greenwich Mean Time (GMT) when referring to it without counting exact accuracies. Greenwich Mean Time (GMT) is not the time when the United Kingdom observes summer time in the northern hemisphere during the summer months. The case is handled by Michael A. Lombardi, a measurement engineer in the Time and Frequency Division at the National Institute of Standards and Technology in Boulder, Colo.

The UTC stands for Coordinated Universal Time.

## Seconds | Time units

Secondly, the basic temporal units that are now determined by the radiant frequencies at which the atomic nuclei of the caesium atom move from one state to another. This second was previously known as 1/86,400 of the mean sundays, i.e. the mean rotational cycle of the earth around its sun orbit.

1956 the second was newly definition by the International Committee for Weights and Measures as 1/31.556.925.925.9747 of the length of the tropic (seasonal) year 1900. 1967 the thirteenth General Conference on Weights and Measures temporarily classified the second as 9,192,631,770 radiative cycling associated with the passage between the two hyper-fine stages of the earth state of the caesium-133 atoms (see nuclear time).

We chose the number of radiative cycling so that the length of the seconds corresponds as exactly as possible to that of the now obsolete seconds of the ephemeris time (defined as the portion of the tropic year given above). Since the Earth's rotational speed is changing all the time, it is necessary to sometimes append (or in theory subtract) a second during the year to make sure that the Coordinated Universal Time (UTC) scale remains synchronous with the natural world.

But why is one moment split into 60 seconds, one moment into 60 seconds, but there are only 24 hrs in a workday?

Lombardi, Measurement Technician, Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colo. The most common number system in today's modern society is decentralized (base 10), a system that probably has its origin because it makes it easier for people to finger-code.

However, the civilisations that initially subdivided the tag into smaller parts used different number frameworks, especially Duo Decimal (base 12) and Sexagesimal numbers (base 60). Due to documentary proof of the use of solar clocks by the Egyptians, most historians attribute to them that they are the first civilisation to split the days into smaller parts. Initially, a sundial was a simple stave placed in the floor, indicating the time by the length and orientation of the resulting shade.

These divisions reflect Egypt's use of the twelfth-decimal system - the meaning of the number 12 is usually traced either to the fact that it corresponds to the number of moon cycles in a year or to the number of wrists on each wrist (three in each of the four hands, without the thumb), so it is possible to measure up to 12 with the palm of theumb.

Probably the next generations of sundials were the first to depict what we now call the time. Even though the times within a given diurnal season were approximately the same, their length varies throughout the year, with the summers being much longer than the winters. In the absence of man-made lighting, the people of that era considered sunlight and darkness as two opposite areas and not as part of the same workday.

However, at the time when solar clocks were first used, Egypt's astronomers also began to observe a series of 36 planets that shared the sky's orbit equally. Transition of the darkness could be characterized by the emergence of 18 of these star, three of which were associated with each of the two dawn times when the star was hard to see.

Full dark periods were indicated by the other 12 star, which in turn led to 12 separations of the nights (another pitch of the twelfth system). Throughout the New Kingdom (1550 to 1070 BC), this measurement system was streamlined to use a series of 24 satellites, 12 of which mark the transition of nights.

It was also used to measure time at midnight and was perhaps the most precise chronometer of antiquity. Discovered at the Ammon Temple in Karnak and dating back to 1400 BC, the watch was a receptacle with inclined inner faces to reduce hydrostatic pressures, labeled with a scale that indicated the separation of the 12 parts of the midnight hours during different periods.

Hisarchus and other Greeks were using methods of astronomy previously devised by the Babylonians who lived in Mesopotamia. Babylonians performed Astronomical computations in the sexual agersimal system (base 60) which they came into possession of from the Sumerians around 2000 B.C. Although it is not known why 60 was selected, it is particularly practical to express breaks since 60 is the smallest number that can be divided by the first six counts as well as by 10, 12, 15, 20 and 30.

Though no longer used for general calculations, the sexual aging system is still used to determine angle, geographical coordinate, and time. Indeed, both the dial of a watch and the ball of a ball are divided by a 4,000-year-old Babylonian numerical system. Eratosthenes, the ancient Greeks astrophysician ( who was living from 276 to 194 B.C.), used a hexagonal system to subdivide a circuit into 60 parts to develop an early geographical system of latitudes in which the vertical line runs through known places on planet earth at that time.

Hipparchus normalised the latitudes a hundred years later and made them conformable to earthometry. Claudius Ptolemy, in his essay Almagest (ca. 150 AD), declared and extended the work of Hipparchus by dividing each of the 360 latitudes and longitudes into smaller sections. First section, parts minimae primary, or first minutes, was referred to as the " minutes ".

" And the second division, parts miniutae seconddae, or "second minute", became known as the second. However, it was not until many hundreds of years after the Almagest that seconds and seconds were used for daily times. The clock display subdivided the hours into half, third, quarter and sometimes even 12 parts, but never around 60. Indeed, the lesson was not generally considered to be the length of 60min.

For the general population it was impractical to consider taking into account in the late sixteenth centuries tiny details until the first mechanic watches displaying tiny details. Today, many watches and wrist watches still have a single min and do not show seconds. Owing to the old civilisations that define and preserve the division of time, today's societies still design a twenty-four (!) hours per diem, a 60 min. per diem and a 60 sec. per diem.

Once, seconds were deduced by subdividing stellar astronomic occurrences into smaller parts, with the International System of Units (SI) once classifying the second as a small part of the mean sun date and later correlating it with the year. The new characterization heralded the dawn of nuclear time measurement and Coordinated Universal Time (UTC).

It is interesting to note that in order to keep nuclear time in line with stellar time, sometimes leak seconds must be added to it. Thus, not all mins contain 60 seconds. In fact, some few uncommon minute events that occur at a frequency of about eight per ten-year contain 61. Story of the hour.