A leap second will be added to the last minute of 2016 to keep our clocks in sync with the sun, and partners of cloud and networking providers are keeping an eye out for technical problems that extra second can induce.
Beyond extending a year many would like to see come to a close, the common adjustment to compensate for small, unpredictable changes in the earth's rotation challenges the global timekeeping technologies that operators of precision information systems rely on.
Cloud providers are meeting the 61st second of the last minute of the year with carefully planned remediation efforts that highlight the intricate challenges they face in operating global infrastructure.
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"A question as fundamental as the time becomes really challenging when dealing with computers all over the world," said Alex Lovell-Troy, director of solutions engineering at Pythian, an AWS and Google partner based in Ottawa.
For starters, there's no central authority on timekeeping and different approaches to setting clocks are appropriate for different use cases and technologies.
Cloud providers rely heavily on Network Time Protocol for clock synchronization. NTP uses a sophisticated algorithm to select time servers that counters the desynchronizing effects of network latency.
NTP gets systems across the global Internet within tens of milliseconds of UTC, or coordinated universal time, which in 1972 superseded Greenwich Mean Time as the universal standard.
Leap seconds were introduced when the change to UTC was made almost 45 years ago – the one inserted on December 31st will be the 27th since then. The last leap second was added at the end of June 2015.
These minor adjustments can have major impacts on advanced systems like cloud-connected servers, websites, and mobile apps that sometimes need to agree on time to the thousands of a second – about how long it takes light to travel from New York to Boston.
For banking applications, or Internet security, that level of precision is particularly vital.