It was brought about by the railroad companies in 1883 in the US. It looks like it officially reached overseas in 1884 when Greenwich (England) was officially made the standard time (called GMT) that the rest of the world’s timezones were based on (at least until the 1970s when UTC, “Universal Time Code”, supplanted it).
US timezones were officially standardized in 1918 along with Daylight Savings Time. The first nation to use DST was actually Austria, who did it as a cost-saving measure during wartime.
Even thought DST was actually repealed in 1919, but the world went back and forth on it until the 1970s energy crises when it finally stuck (at least in the US and Europe).
France actually refused to adopt Greenwich Mean Time in 1884 even as the rest of the world adopted it (it had actually been used by English sailors since the 1700s) in favor of their system (based on “Paris Mean Time”, which put them at 0-degrees on the map instead of Greenwich). Even when the world switched from GMT to UTC in 1972 they waited until 1978.
The featured image is of the Greenwich Meridian laser. It was erected in 1993 and officially represents the Prime Meridian (separates the North hemisphere from the South hemisphere; it was a brass strip prior to the laser).
What? How? Wonder. 