Created in the 19th Century, Greenwich Mean Time (GMT) originally referred to solar timeat the Royal Observatory in Greenwich ,London. Already used by the British navy to calculate their longitude position from the Greenwich meridian,Rado, it was introduced in the United Kingdom by the Railway Clearing House in 1847. It was then legally adopted as official time throughout GreatBritain in 1880, and then in the entire world for the major part of the 20th Century, before being replaced in 1972 by UTC, Universal Time, Coordinated, due to the inconsistency of average solar time. GMT isusually used in the watchmaking world to designate watches with a second time zone. GMT is based on terrestrial rotation, while UT Conatomic international time therefore the two time measurements are close but not the same. Unlike GMT, UTC offers the current view of time zone division directly linked to the real rotation of the earth, and less variable. F.P.Journe innovates once again with the presentation of the OctaUTC®, a patented system that uses the modern standards of determining time zones in full hours. Mechanically it indicates the different time periods linked with the earth’s geographical positions,including summer and winter hour. On the dial, the local hours are indicated by the blue hands, and linked to the calendar indicating the current geographical time.The rose gold hand indicates the hour of the second time zone on 24 hours,represented by the earth’s 24 time zones.