I don't have a WSJ subscription, so maybe this is explained in the article...
What do they mean by "The plan would simplify the world's timekeeping by making each day last exactly 24 hours".
Does this mean we're going to take the current rotation of the earth around its axis, and divide it by 24 to get hours, which will change our definitions of minutes, seconds, etc?
If we do that, won't we have to keep re-evaluating our time as the Earth slows down?
Or, are they going to take the Earth's rotation around the sun as a year, and calculate back from there, which would make midnight creap backwards ever so slowly over the years away from the actual midnight based on the earth's rotation around its axis?
None of this matters. We can control the length of the days and exactly how much daylight we receive from the sun at anyone point on the earth by simply manipulating the universe with that creative little tool they called "daylight savings time."
What's the big deal?
It's the latter.
The proposal calls for adding a "leap hour" every 500 to 600 years to compensate for sunrise getting later over time.
Despite the whining of the Euro-weenies, it would be possible to maintain two time systems, one with the occasional leap second and one with the leap hour, simultaneously so the world's largest telescopes can still function normally.
You might not understand the advantage if you've never had to make time-dependent software operate through a leap second. I have, and it's a pain in the ass.
All they're doing here is defining a "legal day," which has a specified duration. People who need to account for the actual rotation of the Earth don't use UTC anyway, so this has no impact on the technical community.
I couldn't read the article, so I don't know what is being proposed. In physics, the basic unit of time is the second and physicists want to have a second that is the same from place to place and year to year. The atomic second fills this need. From 1958 till 1972 the definition of civil second and atomic second was different, with the civil second being a fraction of the atomic second, something like 1.0000001296 atomic seconds = 1 civil second exactly. The length of the civil second changed from time to time and there were occassional jumps of 50 to 100 nanoseconds in civil time.
In 1972 all that changed, with the atomic second and the civil second being the same. Civil time is linked to astronomical time, which astronomers call "Universal Time" (UT) and never ever Greenwich Mean Time. GMT is more or less the same thing as GMT, astronomical fussbudgets notwithstanding. Surprising, UT is defined conventionally in terms of sidereal time, time reckoned from the orientation of the Earth with respect to distant stars. The relationship is complicated, there are literally hundreds of terms, but the most significant ones are based on explicit assumptions about the relationship of length of the day to the length of the year. A proposal to scrap leap seconds and return to different definitions of civil and atomic time has merit. Time keeping agencies can distribute time codes in civil time, while scientists keep track of atomic time and astronomical time. Time keeping authorities would agree on differences in their rates so that atomic clocks could be used to generate and distribute civil time. In the good old days, few people cared about esoterica like leap seconds. With the proliferation of GPS and WWV, more people are using high precision electronic time codes. It might well make sense to institute a new time scale and time services based on a civil second that varies with respect to the good old fashioned atomic second.
Yep. Which means that watch and clock company stocks will go through the roof. Everyone will have to get a new watch and a new set of clocks.
I think I will make a long term investment in Seiko and Citizen.