We know the importance of time for humans. But it’s more important in the case of computers where even a millisecond of delay could bring unforeseen consequences. That’s why there is a need for accuracy when displaying time.
Microsoft is adding support for Leap Second to Windows 10 RS5 and Windows Server 2019. As you may know, the concept of Leap Second comes out of a natural phenomenon that happens on the earth.
A leap second is added to the UTC (Coordinated Universal Time) to compensate for the slow down in earth’s rotation over time. Since 1972, a 1-second adjustment is made approximately every 18 months to keep UTC synchronized with the mean solar time.
Understanding how a leap second works might be a little confusing. Usually, computers count 60 seconds from 0 to 59. You may see the clock directly jumping from 59 to 0 when a minute completes.
Adding a leap second means the 61st second is also counted. So, for a single time, the computer counts from 0 to 60 instead of 0 to 59. You can try to get the gist of it with the help of this GIF.
The above is an example of a positive leap second. Increasing the confusion, the concept of negative leap second also exists where 1 second is removed from the day and the seconds will be counted from 0 to 58. But a negative leap second has never occurred.
Even if it’s just a small amount of time, Leap Second is important. The government bodies in both the US and EU have strict rules regarding it.