Friends of the Zeiss

P.O. Box 1041                                                                   

Pittsburgh, Pennsylvania 15230-1041 U.S.A.

Telephone: 412-561-7876

Electronic Mail: < >

Internet Web Site: < >


                                                             NEWS RELEASE


For immediate release: 2005 December 29

For more information -- Glenn A. Walsh:

               Daytime: E-Mail < >

               Evening: Telephone 412-561-7876




Pittsburgh, Dec. 29 – The year 2006 will arrive one second later than normal because of the slowing of the rotation rate of the Earth, due to tidal forces caused by the gravitational attraction of the Moon. A “leap second” will be added to the civilian time scale immediately before the beginning of the New Year at the Prime Meridian (which runs through the Old Greenwich Royal Observatory in England)—this will occur immediately before 7:00 p.m. Eastern Standard Time on Saturday.


From time-to-time, an additional second is added to the very accurate atomic clocks, which control civilian time, to keep the world’s clocks synchronized with the actual rotation of the Earth. This year’s “leap second” will be the 23rd leap second inserted into the world’s time scale since an international agreement was signed starting such time corrections in 1972. The last “leap second” was added in 1998.


So, while each minute normally has 60 seconds, the last minute before the New Year at Greenwich, England (last minute before 7:00 p.m. EST Saturday) will actually have a 61st second.


For more information on this time change:


News Release from the U.S. Navel Observatory:

< >


Bulletin of the International Earth Rotation and Reference Systems Service:

< >


Explanations of Leap Seconds –


U.S. Naval Observatory:

< >


“Tides, the Earth, the Moon, and why our days are getting longer” by Phil Plait:

< >


--30 –