Greenwich Mean Time

With the evolution of Great Britain as a maritime advanced nation, British mariners were observed in maintaining at least one of their chronometers respectively set to Greenwich Mean Time. This practice allowed them to perform specific calculations in longitudinal value from the Greenwich meridian which was incidentally by convection observed to be defined as having zero degrees, a value which was later adopted during the 1884 International Meridian Conference.
Greenwich Mean Time was later used worldwide as a reference point independent of its location which resulted in most of the current time zones using this base to calculate the local time hours which would be observed as either ahead of Greenwich Mean Time or Behind Greenwich Mean Time.
Greenwich Mean Time or GMT is generally associated with mean solar time at London’s Royal Observatory, Greenwich. This time was later used as a reference point for standardizing global time. Greenwich Mean Time is synonymously used as Coordinated Universal Time or UTC. When used in its capacity of a time zone however the name Greenwich Mean Time has been used specifically by British based organizations such as the Royal Navy, The British Broadcasting Corporation or BBC World Service and some institutions in Arab based countries including the OSN Television Network.

Prior to the adoption of Coordinated Universal Time on January 1st 1972, Greenwich Mean Time or Zulu Time was observed as Universal Time or UT which was used in its capacity as an astronomically based concept in the field of technology.
Astronomers today no longer use the name Greenwich Mean Time but rather have been accustomed to pay reference to the term UTC or Coordinated Universal Time. Greenwich Mean Time is still used in the United Kingdom today as recognition of the winter seasons, as summer months are associated with the term British Summer Time.
As such Greenwich Mean Time has often been referred to as Western European Time. Due to the imperfections in the orbital speed and axial tilt, noon day Greenwich Mean Time which should be defined as the time of day the Sun can be observed at its highest point crossing over the meridian, is almost never accurate.
This lack of compatibility when calculated by the equation of time has led to an offset of between 14 to 16 minutes from the actual noon. Thus Noon day has been observed to be the average which in mathematical terms is referred to as the “mean” of the precise event, hence the association in the name Greenwich “Mean” Time.
Greenwich Mean Time throughout history has been effectively used in two capacities, in one instance it has been used in the numbering of hours beginning at midnight and in the second instance has been used in numbering hours starting at noon.
Coordinated Universal Time however does not share this ambiguity as midnight is referred to as starting at zero hours. Today’s Astronomers in order to create a simpler and easier understood version of their observational data have given preference to the instance of Greenwich Mean Time beginning at noon which allows each night to be chartered within a single calendar date.