The National Institute of Information and Communications Technology said Wednesday it will add a so-called leap second on Jan. 1 to bring the super accurate atomic clock into sync with the Earth's rotation.

The first time correction in seven years will be made as part of the global change needed because the Earth's rotation is relatively imprecise.

In Japan, the institute, an independent administrative body responsible for notifying the Japan Standard Time, will add a second before 9 a.m. sharp on Jan. 1.

Civil time is occasionally adjusted by one-second increments to ensure the difference between a uniform time scale defined by atomic clocks does not differ from the Earth's rotational time by more than 0.9 second.

The difference between the two times derives from the fact that the Earth's rotation is gradually slowing.

The leap second system started in 1972 and 22 time corrections have since been made.

Until the last time correction made seven years ago, the leap second had been added almost every 1 to 1.5 years, and the longest period without the leap second had been 2.5 years.

Scientists said the upcoming time adjustment is coming after a long hiatus because in recent years the Earth has been rotating more quickly again, meaning there has been less need to adjust time.