This minute has 61 seconds

The last minute of June is going to be a little longer than usual, though you probably won’t notice.

The world’s official timekeepers will add what’s known as a “leap second” to atomic clocks at the end of June 30, slightly delaying the transition to July.

The extra second puts Earth’s time back into sync with the Earth’s rotation, which is slowed by the gravitational pull of the Sun and the Moon, and impacted by major events like earthquakes.

“Throughout civilization, we’ve been trying to match up our civil calendar with what’s going on in the sky,” says Rob Cockcroft, astronomer and postdoctoral research fellow. “From the ancient Egyptians to Julius Caesar, who inserted two new months into the year to try to get the civil calendar back in sync with the celestial calendar.”

The leap second, like the addition of a whole day to February every fourth year, is one of many tweaks humans have made to their clocks and calendars over time.

“If we didn’t make this adjustment every once in a while, we’d eventually be eating lunch at midnight,” says Cockcroft.

And much like in the past, people aren’t universally happy about the adjustment.

Britain’s transition from the Julian calendar to the Gregorian calendar was a hotly debated issue in the country’s 1754 election. When the change did happen, it was necessary to skip 11 days in the month of September.

That led to the mistaken belief that people’s lives would be shortened by the same amount of time.

Today, the concern is around technology’s ability to handle the leap second.

An extra second added in 2012 resulted in many popular websites – including Reddit, Mozilla and Gawker – experiencing technical problems.