Meta joined the ranks of tech giants in recent times, which will eventually lead to the end of the leap second; the interestingly difficult way human beings account for the smallest changes in the timing of Earth’s rotation. Mark Zuckerberg, the owner of Instagram and Facebook, decided to take action against this discrepancy, which has been increasing for years. A debate regarding this took place at a global conference in the year 2021, and this could even continue further if our planet keeps registering record-short days.
As is the case with many other large-scale tech giants, Facebook is also tired of struggling with the time of a global network of servers against leap seconds, adding between 0.1 and 0.9 seconds every so often to match the Universal Time (UTC). Since 1972, 27 leap seconds have been added. Oleg Obleukhov and Ahmad Byagowi mentioned in a post on Meta’s engineering blog that 27 leap seconds are more than enough for non-solar-scientist types—”enough for the next millennium.”
Timekeeping authorities on an international level add these leap seconds at unpredictable intervals, as the factors which cause them are arbitrary, which can include the position of the moon, earthquakes, the braking action of tides on rotation, mantle flow, the distribution of ice caps on mountaintops, and so on. A leap second is called for by Reference Systems Service (IERS) and the International Earth Rotation when the speed of the planet differs from atomic timekeeping.
On the designated day, at midnight, clocks are adjusted to tick from 23:59:59 to 23:59:60 to 00:00:00. That middle timestamp, which is unusual, leads to coordinated systems going bonkers. In 2012, a leap second took down Gawker, Reddit, and Australian airline Qantas. On New Year’s 2017, Cloudflare, a global network, took a hit. Following that, a number of tech giants have prepared themselves to deal with the next leap second by using either leap smearing or micro-second slowdowns over a long time leading up to midnight, which will also be global-server-friendly.
Engineers at Meta noted that every leap second has been positive so far, but a negative leap second can occur because of the ever-changing rotation pattern of the planet. They also mentioned that this negative leap second might not be easily smeared by computer systems. It is long away from idle speculation.
Recently, on the 29th of July, the Earth experienced a shorter day on record than usual, which was 1.59 milliseconds less than the standard time of 24 hours. It is a part of a trend called general speeding-up. On the 19th of July 2020, the planet recorded the second-shortest day at 1.47 milliseconds, until it recorded another shortest day at 1.50 milliseconds on the 26th of July 2022, which occurred just after one day of Meta’s post related to anti-leap-seconds.
Leonid Zotov, a scientist at Lomonosov Moscow State University, told time and date that he believes the movement of the Earth’s geographical poles, which are asymmetrical, might be at fault. At the same time, he also thinks that, at least for this year, there are 70% chances that a negative leap second will not occur.
Since the troubles caused by the previously occurred two leap seconds, the debate related to leap seconds have been stacking up. In 2015, the last time this led to an official decision at the International Telecommunication Union’s (ITU) World Radiocommunication Conference in Geneva, which was then pushed to 2023. The upcoming conference for time-keepers is expected to occur in Dubai, United Arab Emirates, in late 2023. At that time, an agreement between UTC time-keeping and ITU will expire.
Meta might not be the first to take a step towards fighting against leap seconds, but it might very well end up being great timing.