There seems to be a strong possibility that Coordinated Universal Time (UTC), the world standard time introduced in 1972 and now adopted by most civilized countries, will be signiificantly redefined with effect from 2017 without the knowledge, and certainly without the informed consent, of seven billion users.
Link to NPL 'The leap second debate'
Traditional time, based on dividing the mean solar day into 86,400 seconds, is still the basis of legal time in the UK, where it is known as Greenwich Mean Time (GMT). At any given time and place the sun appears in the same part of the sky year after year, convenient both for sundials and steered solar panels, as well as for navigation independent of GPS.
When UTC was defined it was cunningly reconciled with GMT by the introduction of leap seconds. The exceeding accurate atomic time scale (TAI) based on counting the 'world's best' (SI) seconds' was bound to drift apart from GMT, as there are no gear wheels between the Caesium atom and the Earth's rotation. UTC is a TAI offset by a whole number of SI seconds so that UTC is kept within a second of GMT. Currently TAI is running faster than GMT so this offset is increased from time to time, by the creation of a UTC minute containing 61 seconds, either at the end of a UTC year or at the end of June UTC.
The definition of UTC requires that broadcast time codes and time signals conform to UTC, and that's why the lenghened sixth (or very occasionally seventh) pip appeared in the 'Greenwich' Time Signal (GTS). The time signal no longer signals GMT except for brief periods between leap seconds when UTC coincides with GMT.
The majority of time users are only aware of the effect of leap seconds when they notice that their free-running clocks and watches suddenly become exactly a second further ahead (or less behind) at midnight UTC. Radio-controlled clocks will stay in step with the UTC seconds ticks but lose a second at or soon after midnight UTC.
The proposal is apparently to retain the name 'UTC' whilst abandoning leap seconds, allowing UTC to 'cast off' from GMT. This will make life easier for those designing and maintaining equipment which needs to implement leap seconds. Recently there was a period of several years between leap seconds, so there might have been a new generation who had never encountered a leap second in their career. Applications where precision timekeeping is essential, notably GPS, already avoid the problem by running on a version of TAI (with a fixed offest, and no leapseconds).
In 1972 the notices of leap seconds were distributed through the post, but now the offset between UTC and GMT could be distributed worldwide in real time.if necessary.
An alternative proposal
In my view the above proposal is a case of the 'tail wagging the dog'. I suggest that, instead of casting UTC off from GMT the world take the opportunity reconcile these two a thousandfold better by making the offset an integer number of milliseconds, with leap milliseconds at the end of a GMT hour when required. I suggest that these steps would be easily implemented in time codes (coherent with the 60 kHz MSF carrier) and time signals. Precision equipment would be able to infer the leap milliseconds without needing notice of them. Equipment for everday use, even stopwatches for sporting events, could be based on this 'new UTC' without problems.
It took hundreds of years to reform the calendar, how can we get a proper consensus on the reform of time?