On the night of 31 December 2016, it was necessary to count 3, 2, 1, 1, have you noticed? When entering 2017 had to be counted another second. Yes, the year that most people considered to be horrible was 1 second longer, and this is science.
A second more to 2016, which was due to the Coordinated Universal Time and the International Land Rotation Service and Reference Systems. Well, this Paris-based service defines time adjustments in order to approximate Earth’s rotational motion with the atomic time scale, the “civil time” adopted by most countries, such as Portugal.
As the Earth’s rotational motion is in slow (slow), it is necessary to adjust the atomic time, which time is measured on the ground by about 400 atomic clocks, which have an accuracy above normal. This has been the case since 1972 and since then, 26 additional seconds have been inserted (in English they are called leap seconds).
The purpose of the second supplement is that the difference between the time that the clocks (UTC) and the astronomical scale (based on the Sun and the rotation of the Earth) are not greater than 0.9 seconds.
The last second was added to June 2015, and now the International Rotation Service and Reference Systems has decided to add another second at 23:59:59 on 31 December 2016. Since Mainland Portugal and the Madeira Archipelago are in the Coordinated Universal Time Zone, the second extra entered exactly at that time.
So, when I was counting the seconds to open the champagne, either paused or counted another second, even before the entry in 2017.
This is the statement published by the International Rotation Service and Reference Systems: