Recently, technology giants like Meta, Google and Amazon, along with the US National Institute of Standard and Technology (NIST), expressed their dismissal for leap seconds and shared why they wanted to get rid of the concept.
According to the companies, additional leap seconds would be really bad. In a recent blog post, Meta explained: “We bump into problems whenever a leap second is introduced. And because it's such a rare event, it devastates the community every time it happens. With a growing demand for clock precision across all industries, the leap second is now causing more damage than good, resulting in disturbances and outages.” The company concluded that it would be ideal to "stop the future introduction of leap seconds."
According to Meta, leap seconds benefit astronomers and scientists as they help them observe and study celestial bodies. However, the company added that the concept is outdated and not as essential at it once was.
But what is a leap second?
Computers have an absolute sense of time. However, unlike computers, our Earth has inconsistencies. Its spin speed varies depending on geological events and therefore it rotates at an irregular rate. At times it slows down and at times it speeds up. Quite like an average working person. We use these rotations to determine the ‘observed solar time’ (UT1). However, the varying spin speed results in imprecise data.
To make up for this irregularity, the International Earth Rotation and Reference System Services introduced the concept of 'Leap seconds' in 1972. This was an attempt to standardise time across clocks and periodically update the Coordinated Universal Time (UTC) – the time standard across the world as we know it. The leap seconds compensate for the imprecision of the ‘observed solar time’ and help us regulate a universal standard of time.
So far, there have been 27 leap seconds added to the common clock.
Computers operate on precision. For a computer, there are 24 hours in a day, 60 minutes in an hour, and 60 seconds in a minute. However, when leap seconds are introduced, computers comprehend that as 23:59:60 instead of the normal 23:59: 59. According to Meta, each time a leap second is introduced, computing time gets confused and and crashes large websites.
What's the alternative?
The leap seconds help maintain a time standard. The absence of it would leave us with imprecise observed solar time. However, Meta suggests an alternative – smear second, which means slowing down digital clocks over a longer period to account for the extra time to be added, effectively smearing the necessary leap second across a period of hours in a single day.
However, the problem that this approach creates is that there are multiple ways to calculate a smear second. This does not allow any scope for standardisation – the lack of which can cause further outages and confusions.
While Meta has not put a finger to any particular alternative, the company has clearly described the need for one.