The Earth's rotation is slowing down, so an extra second is being added to Coordinated Universal Time (UTC) on June 30, 2023, to keep our clocks in sync with the Earth's rotation.

The Earth's rotation is gradually slowing down due to the tidal forces of the Moon and Sun. This means that each day is getting longer by a tiny amount. Over time, this adds up, so an extra second is added to UTC every few years to keep our clocks aligned with the Earth's rotation.

The extra second is called a "leap second." Leap seconds are added at the end of a month (usually June or December) to make sure that UTC stays within a second of the Earth's rotation.

What countries observe leap seconds?

Most countries in the world observe leap seconds. However, some countries, including China and India, do not observe leap seconds. This means that their clocks can be off by a second compared to UTC.

What happens when a leap second is added?

When a leap second is added, clocks around the world are advanced by one second. This can cause some technical issues, such as software errors or problems with scheduling. However, most systems are designed to handle leap seconds without any problems.

What if a leap second was not added?

If a leap second was not added, our clocks would gradually get out of sync with the Earth's rotation. This could lead to problems with navigation, communication, and other systems that rely on precise timekeeping.

How often are leap seconds added?

Leap seconds are added irregularly, as needed. The last leap second was added on December 31, 2016. The next leap second will be added on June 30, 2023.

Is there a better way to keep time than using leap seconds?

Scientists are working on new ways to keep time that do not rely on leap seconds. One possibility is to use atomic clocks, which are extremely accurate and do not drift over time. However, atomic clocks are very expensive and not practical for everyday use.

For now, leap seconds are the best way to keep our clocks in sync with the Earth's rotation.