But the Earth, Moon, and Sun—massy orbs of rock and fire—do not behave so predictably. Some years, interactions between the three make the Earth orbit a little slower; sometimes, a little faster. In order to keep UTC noon synced to solar noon, the International Earth Rotation and Reference Systems Service adds or subtracts a second to the global UTC every so often. On Monday, it did this most recently, decreeing that June 30, 2015, will last one second longer than the usual 86,400.

But even more than that extra instant in June, leap seconds are having a moment right now. In November, the International Telecommunication Union (ITU) will meet to decide whether to abolish the leap second. The group, an agency of the United Nations, last debated the issue in 2012. It chose to preserve the status quo and re-visit the issue in three years.

The United States is officially against leap seconds. The national position on such matters is determined by the State Department, Matsakis said, but as an advisor on the matter he said he could summarize why the U.S. supported their abolishment: “the real world impossibility of reliably implementing leap seconds.”

“You know [the leap second] exists,” he told me. “Your readers will know it exists for a month, then they’ll forget.”

But most people—including commercial programmers, who write the critical software that controls public and private infrastructure—don’t know about the leap second, Matsakis said, and that means their code doesn’t account for it. So when a new leap second rolls around, things break. Reddit, LinkedIn, and Yelp all suffered issues related to the last leap second in 2012. And, more seriously, computer booking systems used by Qantas Airlines all struggled, delaying flights by hours.

In some cases, it is impossible to update systems before the next leap second arrives. Matsakis spoke of a Switzerland power company whose backup systems only turn on when needed—otherwise, they sit disconnected from the network. When they were activated in a test after the last leap second, they crashed.

Had they been needed at the time, Matsakis said, parts of the country would have suffered a blackout. As a Naval Observatory spokesman told the New York Times in 2012, getting rid of the leap second “removes one potential source of catastrophic failure for the world’s computer networks.”

But wouldn’t abandoning the sometimes-second eventually divorce the Earth from the sun? This is one of the reasons why Canada, China, and Britain all cling to the leap second, or, at least, did at the last global meeting.

Matsakis thinks such a link has already been lost.

“​We don’t have a connection,” he told me. “We lose the connection twice a year when we go on daylight saving time.”

By the end of this century, the accumulated gap between UTC and what-should-be-the-solar-time would only be about one minute.