The leap second debate
2 Feb 2012
The decision as to whether or not to abolish leap seconds has been deferred until at least 2015, after a meeting at the Radiocommunications Assembly in Geneva.
You will probably have seen a lot on the debate about leap seconds in the news recently. In the end there was a favourable outcome for BIS and the National Measurement Office (NMO) with the decision as to whether or not to abolish leap seconds being deferred until at least 2015, after a meeting at the Radiocommunications Assembly in Geneva.
Leap seconds are periodically added to UTC in order to keep the time measured by highly accurate atomic clocks in step with time as measured by the earth’s rotation – which is not as uniform as atomic transitions and is very gradually slowing down.
The Government’s position is not to change the current system as the insertion of leap seconds to the international timescale – Universal Co-ordinated Time (UTC) – remains the best way to balance people’s everyday experience of time with the precision needed for specialised purposes, e.g. operating satellite navigation systems. Leap seconds have been in use for almost 40 years and the international community needs to be absolutely sure before making any changes to a system that works for the vast majority of users.
Ofcom colleagues presented the UK case, alongside Robert Gunn, Director of National Measurement System (NMS) Programmes at NMO, with technical support from time experts from NPL. Ahead of the meeting, support for the UK position was increased by briefing FCO diplomatic posts throughout the world to explain our arguments to their host governments.
Future discussions will focus on better understanding the broader social implications of the potential change and hopefully a decision that the international community agrees on can be reached. For now, NPL and other standards institutes around the world will continue to add leap seconds into the timescale and the link between UTC and Solar time will remain – by the way, the next leap second will be at midnight on 30 June this year.
More information on the NMO, NMS and Leap Seconds.
