Microsoft is bringing support for leap seconds - yes, that one extra second - to Windows, starting with Windows 10 Redstone 5 and Windows Server 2019. With the upcoming updates for Windows 10, Microsoft's operating system now deals with leap seconds in a way that is incredibly accurate, UTC-compliant, and traceable. Leap seconds typically occur every 18 months, resulting in one extra second. The extra leap second occurs to adjust with the earth's slowed down rotation, and an extra second is added to UTC in order to keep it in-sync with mean solar time. To deal with the extra second more appropriately, Windows 10 will now display that extra second, instead of directly jumping to the next one, making it the world's first OS to have full support for leap seconds.
http://osnews.com/story/30593/Window...r_leap_seconds
Windows 10 getting support for leap seconds
19th July 2018, 14:51
Windows 10 getting support for leap seconds 
