This June 30th (tomorrow), a sliver of time will stop across the globe. But nothing to worry, it will stop only for a second, according to the researchers. An extra leap second will be added to the world clocks by the researchers to make sure atomic clocks are in sync with the Earth's rotational time. The phenomenon is similar to how the leap years align our calendars with Earth's revolution around the Sun. In the same way, leap seconds adjust for Earth's rotation and to catch up with atomic time.

How time is calculated?

In simple terms, time is calculated based on the Earth's revolution around the Sun, its rotation and its own axis. One complete circle around the sun is a year, while a complete circle in its own axis makes a day. The day is then divided into hours, minutes and seconds. Most of our clocks are based on mean solar time, in which time is measured by assuming that the Sun is at the same position after 24 hours, relative to the earth.

The world follows the Coordinated Universal Time (UTC). Introduced on 1st January, 1960, the UTC is being adjusted by adding a leap second in the last minute of June or December. The International Earth Rotation and Reference System Services announce the addition of the extra leap second. For this synchronization to come into effect, time will be stopped by a second on the 30th June, since the last minute of June will have 61 seconds.

How the extra leap second will affect computers?

The extra leap second cannot be predicted as the time taken by the Earth to rotate in its axis depends on the dynamics of the earth's core, variation in the atmosphere and oceans, ground waters etc and it can affect the computing systems that follow the Gregorian calendar. Thus, major web-based services will suffer because of an extra leap second which was added three years ago.

For example, if a computer is asked to perform a task at the very time the extra second is added, the computer will be unsure what to do and if an email is received at the very second, it might be stuck in the wrong server. Google predicted this problem and came up with an update called 'leap smear'. Google altered its servers so that they would add that extra second to catch up with the new time.