An EDA tool for validating predefined timing paths having corresponding timing constraints in an integrated circuit (IC) design has a processor that performs a static-timing-analysis (STA) of the IC design and generates a STA report that includes the first set of timing constraints, which include a first number of clock cycles required for propagating the first multi-cycle timing path. A simulation-based checker based on a STA that counts a second number of clock cycles that is actually required by the first multi-cycle timing path to propagate is generated while performing a unit-delay, gate-level netlist simulation of the first-multiple cycle timing path. The first set of timing constraints then are modified so that the first multi-cycle timing path is redefined to require the second number of clock cycles to propagate.