Leap Second Added to the Global Time Scale
International time standards stopped being defined by astronomical observations several decades ago. They now rely on atomic clocks with superior precision. Leap seconds are added or removed occasionally to adapt global time to the actual rotation of the earth, which actually varies slightly over time.
Netnod operates public time servers for the Internet utilizing NTP - the Network Time Protocol. In order to adjust the time in the servers for the leap second, Netnod's NTP service will be interrupted shortly before 23:59:59 (UTC time, that means 01:59:59 Swedish time) and rerestarted again shortly afterwards. This will prevent the servers from giving out incorrect time during the actual event.
Netnod operates this service in cooperation with SP Technical Research Institute of Sweden, national time keepers in Sweden.
More information about leap seconds:
https://en.wikipedia.org/wiki/Leap_second
More information about SP's Time Service:
http://www.sp.se/en/index/information/national_and_international_time/Sidor/default.aspx
More information about Netnod's NTP service: