On Fri, Dec 23, 2016 at 3:08 PM, Dave Horsfall <dave@horsfall.org> wrote:
Let me be the first to say that the International Earth Rotation Service
has announced that there will be a Leap Second inserted at 23:59:59 UTC on
the 31st December, due to the earth slowly slowing down. 

A year and half ago, a running Multics emulation (Multics, so slightly on topic) was crashed by the leap second. An improbable race condition in a in a messaging library used by the DPS8M emulator fired an assertion, bring the whole thing down.

-- Charles