Sometimes someone proposes removing all time zones and using one clock for the whole planet. Then the time is the same everywhere at the same moment. When the clock shows 08:00 in London, it also shows 08:00 in New York and Beijing. But in New York the sky is dark, as it usually is at 03:00. In China it is late in the afternoon. This idea sounds strange, but many groups already use one clock. Airlines, militaries, the International Space Station, and agencies such as NOAA all use one global clock, UTC. They do this because an error in the calculation between two time zones is dangerous in aviation or on a spacewalk. Arthur C. Clarke suggested the one-clock idea in 1976. An economist and an astrophysicist at Johns Hopkins University made it part of a proposal to change the calendar. But this system does not remove the problem. Each region still opens its shops, starts its schools, and eats lunch at the UTC hour that matches its daylight. So the "business hours" are 13:00 to 21:00 in one place and 22:00 to 06:00 in another place. This system replaces time-zone offsets with local customs, and those customs do the same work. Also, the date changes in the middle of the afternoon in parts of the Americas and the Pacific. Previously:• Scientists explain our dislike of Daylight Savings Time READ THE REST