Hi guy. Sorry to bother you
What is “GMT-0400 (EDT)?”
Thanks. I never noticed it before.
5.56mm
GMT = Greenwich Mean Time: https://en.wikipedia.org/wiki/Greenwich_Mean_Time
Greenwich Mean Time or GMT is the clock time at the Royal Observatory in Greenwich, London. When the sun is at its highest point exactly above the Prime Meridian, it is 1200 noon at Greenwich.
GMT is still widely used as the standard time against which all the other time zones in the world are referenced. It is the same all year round and is not affected by Summer Time or Daylight Saving Time.
GMT was originally set-up to aid naval navigation when travel around the globe started to open up with the discovery of the “New World” (America) in the fifteenth century.
Read more here about the connection between accurate time-keeping, GMT and sea voyages.
GMT was not forced on to “land-lubbers” until the introduction of the railways (railroads) in the ah, I need " mid-nineteenth century. The developing railway network meant that Britain needed a national time system to replace the local time adopted by major towns and cities. As Greenwich, due to the presence of the Royal Observatory, was the national centre for time and had been since 1675, the choice was obvious. Nevertheless, GMT was not adopted officially by Parliament until 2 August 1880 .
EDT = Eastern Daylight Time: https://www.timeanddate.com/time/zones/edt
GMT is known in Aviation radio lingo as “Zulu” time, as opposed to local or “Lima” time. GMT is also known as “Coordinated Universal Time”. There is a short-wave radio station broadcasting out of Ft. Collins, CO, call letters WWV, which does nothing but broadcast the time, which refers to it as Coordinated Universal Time.