Leap seconds - UK opposes change

[Douglas Bateman]

Dear all,

The Editor of our Bulletin asked me do write a short note on the proposed elimination of leap seconds, and various links led me to the official point of contact for comments, Mr John Lee, Department of Trade and Industry.

He replied to a query about the consultation process as follows (31 Oct):

Dear Mr Bateman,

There is no formal consultation on the leap second issue. The UK Government line has been decided, which is that we shall strongly oppose the US proposal.

You might like to see the attached paper, which I prepared earlier this year. Please feel free to use any of this in your Bulletin.

Regards,

John Lee
National Measurement System Directorate
Department of Trade and Industry
151 Buckingham Palace Road
London SW1W 9SS

Email: [EMAIL PROTECTED]
Tel:     020 7215 1416
Fax:     020 7215 1350

In his paper (57 KB, which I will forward if asked) he gives a concise background to current time scales, and in para 2.5 he gives a reminder about the current situation.

2.5 The primary reason for introducing the concept of the leap second was to meet the requirement of celestial navigation to keep the difference between solar time and atomic time small. However this motivation for the leap second has diminished because of the wide availability of satellite navigation systems such as GPS. In addition, it is alleged by some that the operational complexities of maintaining electronic systems relying on precise timekeeping have made the insertion of leap seconds increasingly difficult and costly.

He then states that the change would eventually force legislation to change our legal timescale (the old GMT, and in practice UTC). It is also strongly opposed by astronomers.

Details of the reason for the change are given (some of which have been given in the earlier correspondence) and he states:

3.4 The strongest advocates of the proposal come from the US military. They have been unwilling to say exactly what problem they are trying to fix. Commentators are divided as to whether there is a problem with the Global Positioning System (GPS), but there remains a possibility that some of the ground elements of the GPS do not handle leap seconds very well. Some IT and telecoms networks might be affected by leap seconds, but the debate on the issue is evenly balanced as to whether this is a serious problem.

I have put in bold the rather alarming statement that the US military will not say what the problem actually is!

On the subject of other opinions, the paper states:

INTERNATIONAL VIEWS

5.1 A survey of international scientific bodies, carried out by the IERS in 2002, has shown that most scientific users are neutral, a significant minority is strongly against the change, and a small minority is strongly in favour of change.

5.2 At an international colloquium on the leap second issue in 2003, the consensus was that there should be no change until 2022, thereby allowing telescope software to be modified or replaced over a long period. The US has ignored this consensus in promoting the current proposal. It was proposed at this meeting that a new international timescale without leap seconds should be given a new name (such as Temps International) to avoid confusion with the timescales linked to astronomic time. The US has also ignored this view, and wishes to retain the name UTC for the new timescale.

5.3 At the meeting of Working Party 7A of ITU-R in October 2004, the UK was the only country to object to the US proposal. If we want the US proposal to be implemented then we can simply withdraw our objection. However if we seek to block it, we will need the support of other countries.

Given that decisions could be made this month, I again checked with Mr Lee and received the following (1 Nov);

Dear Doug,
 
The only country to have declared its position so far is Germany, and they will go along with the US proposal. I do not expect to know other countries' views until the meeting.
 
The proposal will be debated at Working Party 7A of ITU-R during November. The US will press strongly for the existing Recommendation on UTC to be amended, and the UK will oppose it. I am not sure what the outcome will be.
 
Regards, 
 
John

For sundial watchers, all we can do is wait and see.

Regards, Doug