When was the idea of a global time standard born and what changes has it undergone to this day?
UTC stands for Coordinated Universal Time , a standard used to establish all time zones in the world. For example, New York City is in the UTC time zone minus 5 (UTC -5) which means that the time on a UTC clock will go 5 hours ahead of the time in New York.
According to Space , the idea behind universal time was first thought of at the end of the 18th century, when railroads and shipping lines were connecting the world and the need for standard timetables to coordinate operations. economic movement. Previously, the time of day was calculated according to whatever time the local clocks showed. But local time can vary by seconds or even minutes – what a scary situation when you’re late and want to know if you can catch your train at the station.
The world clock in Berlin shows the time synchronized to UTC in 148 cities.
Weather observations around the world (including surface water, radar, etc.) always need to be made according to a standard time. Thus, in 1884, several nations met at the International Meridian Conference in Washington DC to figure out how to synchronize clocks around the world. The lines of latitude running from East to West around the earth are measured from the equator, but there is no universally agreed equivalent for longitude lines running from north to south. At the conference, 41 delegations from 25 countries chose the prime meridian – the zero point for meridians, which is the location that passes through Greenwich in the UK, according to TheGreenwichMeridian.org. The standard time for clocks since then is called Greenwich Mean Time (GMT, Greenwich Mean Time) . Then GMT is equivalent to universal time (Universal Time-UT).
By the middle of the 20th century, a new technology, the atomic clock, which could measure time with incredible accuracy, showed that the Earth’s orbit actually differs slightly each day. Earthquakes, melting ice sheets and natural oscillations in our planet’s motion can cause changes of a few fractions of a second in the time it takes for the earth to rotate around its axis. NASA.
So, in 1967, a United Nations committee officially adopted UTC as a more precise standard than GMT in setting clocks. UTC includes measurements of the Earth’s orbit as well as the average time from 400 electronic clocks worldwide, according to timeanddate.com.
After a few adjustments, in 1972 UTC was added a number of leap seconds to keep up with the earth’s orbit, which is irregular and less accurate than electronic clocks.
Until 1972, Greenwich Mean Time was equivalent to UT. After UTC was adjusted, GMT is no longer a time standard but is just the name of a time zone used in a number of countries in Western Europe, Africa , including the United Kingdom during winter, and also in winter. year in Iceland.
In summer, Britain uses the BST (British Summer Time) time zone, which is one hour ahead of GMT.
Royal Observatory Greenwich, the official home of the prime meridian and GMT. (Photo: Britain Express).
Vietnam we are using time zone UTC +7.
This abbreviation is a compromise between English and French speakers:
The English Coordinated Universal Time is abbreviated as CUT, and the French Temps Universel Coordonné abbreviated as TUC.
This UTC time frame is administered by the international office of mass and length (BIPM-Bureau International des Poids et Mesures) based in Sèvres, France.
The US military has divided the Earth into 25 standard time zones according to the letters, of which GMT is also known as Zulu time or Z time because it is located in Z time zone, and Zulu is the code word for the letter Z in the alphabet. the international radiotelephone spelling alphabet, is the most widely used radiotelephone spelling alphabet.
Time zones east of Greenwich are assigned the letters A through M (except for the letter J), and time zones west of Greenwich are assigned 12 letters from N to Y. The letter J is not used.
The table below is the 25 standard time zones assigned by the military with 25 English letters and time zone names according to the region of the world:
Time zones in East Greenwich:
Time zones in West Greenwich:
