On June 30 at 11:59:59 p.m. EDT, one second will be added to clocks in the United States. The "leap second" will be added to the Coordinated Universal Time (UTC), raising the question if atomic clocks alone should be used to keep "civil time."
UTC is the international standard time for civil time. The International Earth Rotation Service (IERS) in Paris, France made the decision that the extra second would be added to Earth's time measurement, according to ABC News.
Unlike Earth's leap year that is related to the planet's solar revolution, the 2015 leap second has become controversial. The leap second impact could include problems with computers and websites that were not designed to handle it.
That is exactly what happened when an extra second was added to clocks on June 30, 2012. Companies that had problems with the added second included Linkedin and Yelp.
The IERS explained that the leap second month could have been either June or December. Since the leap second implementation in 1972, Earth has gained 25 seconds and lost 0 seconds.
"Civil time" is based on the UTC's 24-hour time standard. An atomic clock and the Earth's rotation are combined to keep the time.
UTC is used by nearly every country in the world, keeping uniform time in the 24 time zones. But UTC time is unrelated to time zones. It is set within each particular time zone.
Scientists know that the Earth's rotation has gradually been slowing, which affects the length of days and the need for leap seconds. However, International Atomic Time (TAI) is also important for time-sensitive devices.
Some scientists argue that a leap second is unnecessary. Peter Whibberley, of the UK's National Physical Laboratory, noted that atomic clocks keep more precise time than Earth does, according to Digital Journal.
In fact, countries such as the U.S., France, and Japan want to eliminate leap seconds. Meanwhile, other scientists argue that a "leap minute" should be added from time to time.
Regardless of whether atomic clocks or Earth spins are used to keep civil time, one thing will remain true: every second counts.