 We are at ITU looking at the future of the international timescale. And I have with me Elissa Felicitas Arias, who is the director of the time department of BIPM, which is the Bureau Internationale des Poires de Mzio, which is the International Bureau of Weights and Measures in Sebra in France. Dr Arias, we are here to debate the international timescale and whether to eliminate the leap second in the universal time coordinates. What is your opinion on that? This has been a debate for many years, not only at the ITU, but also in other organizations. There is an opinion, which is my personal opinion, but is also the opinion of the International Committee for Weights and Measures, that UTC without leap seconds could be of benefit for all the modern applications that request for a continuous timescale. Why is that? Because technology has evolved since 1972, when UTC with a leap second adjustment was adopted, and technology, as it is today, makes use of very good synchronization of networks and makes use of continuous timescales for the purposes of synchronizing systems, such as global navigation satellite systems. So this leap second that was good for navigation in the 70s is no more good for space navigation. Would the elimination of the leap second have consequences on ordinary uses? Not at all. What is important to note also is that the purpose of a leap second is to bring coordinated universal time, atomic, closer to the time that can be derived from the rotation of the earth. In a way, there is a feeling that this makes coordinated universal time close to solar time. And there is a feeling that we are strictly coordinated to solar time in our activities. In fact, this is not the case. I will not make a really difficult description of this issue, but I will just give one explanation. We have legal official times in every country, and this is used for civil timekeeping. These legal times do not correspond to solar time in any place of the country. They correspond to one meridian. So who is living in a country, if he is living exactly on the meridian that is used for the civil time will be more or less in solar time. But if you are living out from that meridian, of course you are shifted from solar time. In many countries, for example, we did some numbers for France, you can have differences that can go up to two hours between solar time and legal time in the territory. So you are saying that solar time is what we live under the sun and otherwise we are really living in standard time in time zones. We live in time zones and even I would like to add one more factor that is daylight saving times. We are very used of changing the clocks in one hour between summer and winter. So this increases the difference between solar time and legal time once per year. So for people, think that we will maybe differ in one minute from that, let's say, solar time in about more than one century. Who will realize that in the life of a human being? Nobody. A leap second is something that we should now eliminate? In the opinion of most communities and in my personal opinion and also for the safety and for a better time coordination in the world, we should make a decision. But not everyone agrees? Not everyone agrees and there are different reasons for not agreeing. Some reasons are technical but systems need to be adapted and this is true. Systems need to be adapted but this has been the case each time technology had a big step in the evolution. So systems need to be adapted. This has a cost and we live in a world where we try to save money and not to spend it. So this has a cost. This has a lot of human contribution but I would say that the insertion of a leap second is also costly. Why is that? Because a leap second following the recommendation of the ITU is to be inserted following a clear procedure at the same time in all clocks in the world. When you say all clocks that means that all the systems that are relying on time from that particular clock need to be checked and if necessary also adapted. So it is complicated. It requests a lot of coordination. It requests human intervention because you need to check that all your systems are working properly. So it is costly. Just an example of how maybe not difficult but that consequences might come from this application is that the space agencies do not planify a rocket launching on the possible dates of application of leap seconds even if there are no leap seconds announced. So this has a reason. That's very interesting. But are there any political or cultural objections to this? Certainly, certainly. There are cultural objections coming from countries where standard time has a tradition. So it is very, very frequent to find GMT as the time reference and we should say that GMT is legal time in the United Kingdom but GMT is not international time since 1948. What happened in 1948? 1948, the International Astronomical Union introduced universal time UT as the reference for time and then in 1972 the ITU defined coordinated universal time was a leap second as the successor of universal time from astronomical definition. So culture in United Kingdom makes difficult to accept that GMT will diverge from coordinated universal time because GMT has the flavor of solar time and of course, yes, it will diverge and then there are some other objections some time religious objections but not very often objections with the technical support. So you would say that technically and scientifically of course it's very important to eliminate the leap second. So at the end of the day when we do eliminate the leap second we won't be living at midnight at 12 o'clock noon. No, no. If this happens this will be glaciations maybe. Thank you very much Dr. Arias for coming to ITU TV Studio. Thank you very much to you.