In this study, a highly precise time domain solution of electromagnetic fields for a canonical structure is derived. Our reference solution is extremely useful for researchers, engineers, and developers to evaluate the accuracy of their computational results using commercial software or their self-developed codes. Rigorous solutions of a cylinder or sphere, which consists of a homogeneous medium, are derived in the complex frequency domain; they are numerically transformed into the time domain using fast inversion of Laplace transform. In addition, the field distribution at the desired specific observation time can be easily obtained. Furthermore, the numerical accuracy of the computational electromagnetic solvers is evaluated. INDEX TERMS Reference solutions, time domain solver, fast inverse Laplace transform, finite-difference time-domain, nonlocal effects.