Variations of major fundamental frequencies of the solar system over the time interval from −35 Myr to 5 Myr with origin at J2000. These frequencies (in arcsec yr⁻¹) are computed by applying the NAFF algorithm to the proper modes of the secular solar system associated with major planets. The errors in the resulting frequency samples are estimated as the difference between the frequencies computed respectively from the original ephemeris and its quasi-periodic approximation. Also shown in this figure are the Chebyshev approximations of these varing fundamental frequencies (red curves), which are specified in Table A.2.