 I have with me Mr. Vincent Means, who's head of the Frequency Bureau of La Sontre Nationale de la Thude Spatial, the French National Center for Space Studies. And he's also chairman of the ITUR Study Group for Science Services. Vincent, I'm very pleased to have you here. But I wanted to talk to you about the leap second today. Yes. The leap second has been a matter of debate for some time and a lot of concern as well for some areas. What exactly is the leap second? Well, the leap second, if you will, is a way to have the current time scale, which is based on its anatomic time scale, to be sure that this time scale, which is with the seconds which are absolutely uniform, to be in relation with the time that can be measured through the rotation of the Earth and the apparent motion of the Sun. And because the Earth's rotation is not something which is uniform, sometimes the Earth can accelerate, sometimes it can slow down, and we have to adjust what we call UTC, the universal time coordinated. We have to adjust that with a leap second, so a second that we insert so that the difference between the time that is the UTC time and the time based on the rotation of the Earth around itself and around the Sun, that difference is less than 0.9 seconds. And when you see that there is a deviation of more, that will be more than 0.9 seconds, then we insert an additional second. Actually, we have always inserted an additional second, but we could take out a second as well, but it depends whether the Earth slows down or accelerates. Usually the Earth slows down, but it could accelerate as well. So basically, that's a way to make sure that UTC is always very close to what we call UT1, which is the time based on the rotation of the Earth around itself and around the Sun. But the discussions have been about eliminating the leap second. Now, where do the discussions stand on this? Well, currently, we have basically within the studies that have been made in Working Party 7A, which is the responsible working party for this aspect. We have two options. We have a first option, which is we eliminate the insertion of the leap second. And so UTC becomes a continuous time scale. We don't have any break within this time scale. The other possibility is that we keep UTC as it is today, so regularly we will have the insertion of a leap second. But beside the UTC time scale, we propose to disseminate another time scale, which in that case would be a continuous time scale without leap second. So the idea is to have two time scale disseminated simultaneously for the people to use. Either they need a time scale with a leap second, or they prefer to have a continuous time scale. But what is the reason to eliminate, what are the technical or scientific reasons to eliminate the time scale, the leap second? The leap second, actually, the problem of the leap second is we never know when there will be a leap second. It's only by measuring the time based on the rotation of the earth that we know whether that deviation, that difference between this time based on the rotation of the earth and UTC is more or less than the airport mine second. Sometimes you can have magnetic movements or atmospheric movements, which will slow down the earth more or less. And sometimes you will need a leap second every year to adjust UTC with the rotation of the earth. And sometimes, and it happened several years ago, we were five years without leap second. So it really depends on the observation of the rotation of the earth. So it's not something that can be inserted automatically in systems that require very precise time. And actually, today, all telecommunications system, either computer system or radio waves or just a telecommunications system, they need very precise time for synchronizing the data because everything is digital today. So time is very, very important. And so that particular leap second needs to be inserted manually. So there is a risk of human error. If you recall the last event of a leap second that was in June 2012, there was insertion of leap second and several systems suffered some glitches. There was not very, very serious, but some systems suffered some glitches because of this insertion of the leap second. Nothing was very serious in Europe because that insertion happens at midnight in Europe. But it happens during the middle of the day in Australia, for instance. And then if we take the example of airline reservation, we had a problem with airline reservation because of the insertion of the leap second. And some, a large number of Qantas flight had to be grounded because of the software problem with the insertion of the leap second. Obviously, nothing happened in Europe because everybody was asleep at this very moment. So that created some problems. So by eliminating the leap second, then we eliminate a lot of problems with the synchronization. So why are some people not in the favor of eliminating the leap second? Well, to be completely honest, we have been told that there are some systems that need to have the time very close to the time measured through the rotation of the Earth. So for some system that need to be very close to that particular time, so there may be some problem that would need to be some adjustment in the software used by this system. I believe there are very few systems that are really needing this time based on the rotation of the Earth. But for those systems, there may be some problem. Knowing that the difference between the time, UT1 based on the rotation of the Earth and UTC, is something which is well known and which is broadcasted by the BIPM. So you can have access to that difference with a very good accuracy. What is the BIPM? BIPM is the International Bureau for Weight and Measures. And this is the body which is responsible for the formation of UTC, if you will. So will the elimination of the leap second affect us ordinary citizens in any way? I don't think so, because if you look at what we did in the past with the inception of leap seconds, basically the deviation between the time based on the rotation of the Earth and UTC would be in the order of about one minute per century. Could be a little bit more, could be a little bit less, but in the order of one minute, which means that basically you would have a difference between the time based on the rotation of the Earth and UTC of about 15 minutes or less in 1,000 years. So you will need to wait for 4,000 years to have a difference of at least one hour. Knowing that today nobody lives under the sun, and if you take the example of France since I live in France, there is actually nobody living under the sun in France. What do you mean by living under the sun? Living under the time based on the position of the sun in the sky. So basically when the sun is at the marriage and so the highest point in the sky, it should be midday. So we are living in artificial time. We are living in artificial time. And if you take the case of France, the difference between the solar time and the time in which we leave is between a few minutes to roughly about three hours, depending whether you use summertime or winter time, because we have daylight saving as well. So actually if we don't have the insertion of the lip second, the situation would be better for the French people, because we would adjust to the solar time for some people in a few centuries. But if you take the example of China, for instance, China is much larger than France or Europe, and it's only one time zone in China. So you can imagine that everybody is living under the same time in China, but there is a large difference between those people living in the east of China and those people living in the west. So nobody is really living under the solar time today. So we'll be all right if the lip second is eliminated. Yes, I think we'll be all right. And if there is a need in several thousand of years to adjust, then what we can adjust is not UTC, but just adjust the civil time. Just like we do every year when you have to adjust the time for daylight saving, you have a one hour adjustment from one day to the other. So that could be the same thing that we just decide in 2,000 years that tomorrow, instead of being midday, will be midday and 30 minutes. That's all. So we'll be the same kind of adjustment. So do you think this decision will be finalized at the next World Radio Communication Conference in 2015? I don't know, really, but I hope so. And I hope that we will find a decision since the difficulties we had during the RA, during the Radio Communication Assembly in 2012, was that there were a lot of administration which really didn't know what to think about this problem. Here this is an agenda item. So we have many opportunities to indicate to all the other administrations what are the possibilities. We have a workshop that we have for starting tomorrow and Friday here in the ITU, organized by the VIPM. That's 19th of September. Yeah, exactly. And we have the ITU workshop on the preparation of the conference next December. So we have several opportunities plus the CPM that will take place, of course, in the early 2015. So we have several opportunities to explain to the other administration what the problem is and what are the options that we're proposing to solve this problem. So I hope that WRC 50 will be able to take a decision. So we will have some preparatory meetings for the World Radio Communication Conference. And I'd like to thank Vincent Means for being with us today. Thank you very much, Vincent. Thank you.