There has been some argument for a while about whether it’s worth continuing to maintain leap-second adjustments to keep our atomic clocks in sync (roughly) with the Earth’s rotation. Every time a leap-second is added as the Earth’s rotation slows down, it’s a bit of a headache for various organizations to babysit their computer systems through the change, and fix any glitches that arise. And the rate of addition of such adjustments is only going to increase over the coming centuries. Now, for the first time ever, the Earth’s rotation is (temporarily) speeding up for a change, so a leap-second will need to be *subtracted* this time. When a leap-second is *added*, that day has 86401 seconds, so the clocks tick over from 23:59:58, 23:59:59, to 23:59:60, and then to 0:00:00 for the new day. When it is *added*, the day will only have 86399 seconds, so the clocks go from 23:59:58 straight to 0:00:00, without stopping off at 23:59:59 along the way. Nobody is ready for this, and it seems likely to cause even more problems that have not been encountered before. So a vote will be taken in October to put a stop to further leap-second adjustments; if this goes ahead, UTC (the atomic-clock time reference) and UT1 (referenced to the Earth’s rotation) will be allowed to diverge beyond their current maximum difference of 0.9 seconds in future, until the discrepancy is (according to the article) as much as one hour. What happens after that? Presumably somebody will come up with a bright idea for what to do next, in the centuries between now and then ... <https://www.computerworld.com/article/4220034/leap-second-proposal-will-keep-software-stacks-in-sync-2.html>