The world’s clocks will be forced to stop for a brief second at Tuesday midnight, the 30th of June. That will happen as the “guardians” of time worldwide will add an interstitial second in order to correct the time and as a result the last minute of this month will have 61 seconds instead of 60.
So, at 23:59:59 Greenwich time, we will all notice an extra second (23:59:60) before the clocks show 00:00:00 and the 1st of July begins. Other systems will just turn off for one second.
This is the 27th time something like that is happening. The last time was in 2012 (while some of the previous times were 2008, 2005 and 1998). And in all of those times, some malfunctions occurred on brokerage and the internet, as the central computers of some services such as LinkedIn and Reddit got confused, something that many fear might happen this time as well.
Typically, our planet needs 86.400 seconds to make a 3600 gyration in 24 hours. But Earth is constantly receiving Earth constantly receives gravitational effects from the Sun, the Moon and other planets and as a result, the speed of its rotation is not the same every time as it gets slower and slower. So, the average duration of one spin Is 86.400.02 seconds.
The result is for scientists to observe a divergence of 2 mm of a second between the physical (astronomical) time and the International Atomic Time that the watches are based on. And there some watches that can be pretty accurate…even to the billionth of a second! Now when this divergence to scientists’ calculations stacks up for some time, day by day, at one year there would be a total divergence of one second. So every now and then there has to be a slight correction to the UTC (Universal Time Coordinated), the successor of GMT (Greenwich Mean Time).
IERS constantly monitors the spin our planet and informs the ITU (International Telecommunication Union) about when the time must “freeze” for a second. The first correction was done in 1972. Until then, people used to count time not by atomic watches by based on the astronomical relationship between the Earth and the Sun which was until then known as the GMT.
The extra second is announced months before it has to be added, so that the International community as well as worldwide known and expanded services and companies have enough time to make all the required preparations. For instance, given that most computers used in companies and homes are designed by Microsoft, imagine what would happen to all those companies (banks, brokerages etc), if the extra second was added out of nowhere. Of course there are still some malfunctions going on as we mentioned above, but nothing that can’t be dealt within a few hours.
So, come Tuesday night, we are all going to have an extra second. Have you thought how you want to spend yours already?