This paper presents a new long-term numerical solution for the insolation quantities on Earth, spanning from -250 Myr to 250 Myr. The solution improves upon previous work by using direct integration of the gravitational equations for orbital motion and enhancing dissipative contributions, particularly in the Earth-Moon system. The solution is used for calibrating the Neogene period and is expected to be used for paleoclimatic data calibrations over 40-50 Myr. The most regular components of the orbital solution can be used over much longer time spans, which is why the solution is provided over 250 Myr. The obliquity solution shows a secular increase due to tidal dissipation and a strong decrease due to a resonance crossing. For the Mesozoic time scale, the largest amplitude eccentricity term is used with a fixed frequency of 3.200 arcsec/yr. The uncertainty of this time scale over 100 Myr is about 0.1%, and over the full Mesozoic era is about 0.2%. The solution includes a detailed analysis of the main limiting factors for long-term integrations and the design of new symplectic integrators. The solution is based on a comprehensive dynamical model for planetary orbital motion and a new symplectic integrator. The solution also includes analytical approximations for orbital and rotational quantities of the Earth, which can be used for better analytical understanding of insolation variations. The stability of the solution is discussed, as well as possible chaotic transitions in the main secular resonances. The solution is available on the web and includes routines for computing insolation quantities. The solution is compared with DE406 and La93, showing differences in orbital elements and secular frequencies. The secular frequencies are determined over 20 Myr for inner planets and 50 Myr for outer planets. The solution provides a detailed analysis of the fundamental frequencies of the solution, showing the stability of the considered frequencies over time. The solution is used for paleoclimatic studies and includes analytical approximations for orbital and rotational quantities of the Earth.This paper presents a new long-term numerical solution for the insolation quantities on Earth, spanning from -250 Myr to 250 Myr. The solution improves upon previous work by using direct integration of the gravitational equations for orbital motion and enhancing dissipative contributions, particularly in the Earth-Moon system. The solution is used for calibrating the Neogene period and is expected to be used for paleoclimatic data calibrations over 40-50 Myr. The most regular components of the orbital solution can be used over much longer time spans, which is why the solution is provided over 250 Myr. The obliquity solution shows a secular increase due to tidal dissipation and a strong decrease due to a resonance crossing. For the Mesozoic time scale, the largest amplitude eccentricity term is used with a fixed frequency of 3.200 arcsec/yr. The uncertainty of this time scale over 100 Myr is about 0.1%, and over the full Mesozoic era is about 0.2%. The solution includes a detailed analysis of the main limiting factors for long-term integrations and the design of new symplectic integrators. The solution is based on a comprehensive dynamical model for planetary orbital motion and a new symplectic integrator. The solution also includes analytical approximations for orbital and rotational quantities of the Earth, which can be used for better analytical understanding of insolation variations. The stability of the solution is discussed, as well as possible chaotic transitions in the main secular resonances. The solution is available on the web and includes routines for computing insolation quantities. The solution is compared with DE406 and La93, showing differences in orbital elements and secular frequencies. The secular frequencies are determined over 20 Myr for inner planets and 50 Myr for outer planets. The solution provides a detailed analysis of the fundamental frequencies of the solution, showing the stability of the considered frequencies over time. The solution is used for paleoclimatic studies and includes analytical approximations for orbital and rotational quantities of the Earth.