The epoch ф=J2005.5 is the date 2005 July  2.375  (JD 2453553.875)
  it corresponds to the Besselian epoch B2005.50139

                                         h  m
 Beginning of the spring March     20, 12 33.4 UT
    >>            summer June      21,  6 46.1 UT
    >>            autumn September 22, 22 23.1 UT
    >>            winter December  21, 18 34.9 UT
                                         h
 The Earth at perihelion January    2,  0.6 UT
 The Earth at aphelion   July       5,  5.0 UT