The epoch ’=J2006.5 is the date 2006 July 2.625 (JD 2453919.125) it corresponds to the Besselian epoch B2006.50142 h m Beginning of the spring March 20, 18 25.5 UT >> summer June 21, 12 25.8 UT >> autumn September 23, 4 03.3 UT >> winter December 22, 0 22.0 UT h The Earth at perihelion January 4, 15.5 UT The Earth at aphelion July 3, 23.2 UT