If You Have Ever Been To Canary Wharf,

you will see 6 Swiss clocks,

each one totally accurate as the second hand takes 58.5 seconds to rotate around by 59 seconds, so it is one second short of a minute every minute hardly accurate you would think, 

but then something happens on the 59th second, every 59th second, the second hand pauses, it waits until a nationwide pulse is sent to every Swiss railway clock that a minute has passed, then the clock jumps to the minute and carries on for another 58.5 seconds, totally accurate and on time, if only the UK's trains were!