We support the goal of improving the facilities for providing accurate time signals around the world. This is not the way to reach that goal. The definition of UTC - like all types of Universal Time such as UT1 and UT2 - as a general purpose approximation to the familiar concept of Greenwich Mean Time is critical to astronomical projects, software, and image and catalog data. The history of the redefinition of the term GMT in 1925 attests that a redefined UTC would likewise result in ambiguity and confusion, with the inevitable need for astronomers and society at large to bear the costs of analyzing and replacing all references to UTC in operational and legal systems. This is a mistake we need not repeat.
What should we do instead? Literally - take our time. The current UTC standard is designed to have a life span of hundreds of years. Most systems are not adversely affected by leap seconds since resetting a clock is a common function. Systems that need atomic time are new and specialized and their designers should respond to their own requirements, not transfer them to others. In any event, atomic time is already widely available, for example via GPS. Contrary to the letter in the March Newsletter, the historical and legal reality is that time has always meant Earth rotation because civil time has always been a subdivision of the calendar.
Rob Seaman
seaman@noao.edu
Steve Allen
sla@ucolick.org