Ditching the leap second would mean decoupling clock time from the Earth’s rotation – from day and night itself.
Every now and then — once in two years, say — an extra second of time is legislated into the end of a day. This so-called leap second leads time on a tiny detour, from 23:59:59 to 24:00:00, via 23:59:60. It’s just a second. Most people take no notice. But everyone is affected, because we all share the same civil time, modulated by constellations of orbiting satellites, diplomatic protocols and computer networks. The hour gets doled out to us much the way water comes from the tap — processed and sanctioned, sometimes with an additive or two.
Since 1972, when the leap second was inaugurated, 25 extra seconds have been parcelled out to the public. Each one helped bridge the difference between the way we mark time’s march from day to day, and the way we divide the day. Despite its small size, occasional occurrence and quirky name, the leap second constitutes a cornerstone of our current civil timekeeping system.
In 2015, leap seconds will come up for international review. Four decades of use have allowed time for certain factions to find fault with the leap second, and to question whether periodically resetting all the clocks in the world is actually worth the bother.
I can certainly sympathise with that sentiment. The semi-annual switch between standard time and summer time all but undoes me. Only one of my clocks picks up the radio signal telling its hands when to ‘spring forward’ or ‘fall behind’, and I resent having to fiddle with all the others. Then, too, I find the single hour’s time difference more disturbing to my equilibrium than a multi-time-zone dose of travel-induced jet lag, probably because the seasonal change is imposed upon me. Nothing would please me more than to see my government abolish daylight-saving time, which is already widely ignored by other countries. It is ignored with impunity even by individual states and counties within the continental United States. Ending it at a stroke would not cause the slightest wrinkle in time.