With the Earth completing its revolution milliseconds quicker than average, all of the 28 fastest days on record(since 1960) occurred in 2020.

This is not a dangerous matter as the planet's rotation varies all the time, affected by variations in atmospheric pressure, winds, ocean currents, and the movement of the core.

But it is a disturbing matter for international timekeepers as they use an ultra-accurate atomic clock to meter out the Coordinated Universal Time(UTC). Everyone sets their clock based on UTC. UTC gets a correction as the astronomical time, set by the time it takes the Planet to perform one complete rotation, deviates from UTC by more than 0.4 seconds.

Until now, these changes have consisted of adding a ''leap second'' at the end of June or December to the year, having the astronomical time and atomic time back in line.

The rotation of the Planet has been slowing since the calculation of satellites started in the late 1960s and early 1970s. This helped leap seconds to tack on.

According to the National Institute of Standards and Technology (NIST), Scientists have been adding leap seconds about every year and a half on average since 1972. An extra ''leap second'' was added in 2016 on New Year's Eve at 23 hours, 59 minutes and 59 seconds. This was the last addition of leap second.

The scientists are talking about subtracting the ''leap second'' for the first time. Instead of adding a second, they might need to subtract one.

This is so because the average length of a day is 86,400 seconds. In 2021, the astronomical day will measure in 0.05 milliseconds shorter(on average). This will add up to 19 millisecond lag in the atomic clock over the year.

"It's quite possible that a negative leap second will be needed if the Earth's rotation rate increases further, but it's too early to say if this is likely to happen," physicist Peter Whibberley of the National Physics Laboratory in the U.K., told The Telegraph.

"There are also international discussions taking place about the future of leap seconds, and it's also possible that the need for a negative leap second might push the decision towards ending leap seconds for good."

The year 2020 was astronomically faster than usual. According to Time and Date, Earth broke the previous record for the shortest astronomical day, set in 2005, 28 times.

In 2005, July 5, the shortest day that year completed a rotation of 1.0516 milliseconds faster than 86,400 seconds. In 2020, the shortest day was July 19 when earth completed one spin 1.4602 milliseconds faster than 86,400 seconds.

According to NIST, leap second has both pros and cons. Leap seconds might be helpful in making sure that astronomical observations are synced with clock time whereas it might be a burden for some data-logging structure and telecommunication infrastructure.

At the International Telecommunication Union, some scientists are considering to introduce the "leap hour" letting gap between astronomical and atomic time. They believe that it would reduce disruption to telecommunications. Astronomers should adjust accordingly in the meantime.

The decision on adding or subtracting the leap second is to be confirmed by The International Earth Rotation and Reference System Service in Paris, France. according to the service's Earth Orientation Center, no sign of adding leap second is shown to date.