A method and apparatus for restarting a GPS-based timing system without a GPS signal is provided. More specifically, there is provided a system comprising an antenna, a GPS receiver coupled to the antenna and configured to generate a GPS traceable timing signal based on a GPS transmission, and a timing system coupled to the GPS receiver, the timing system comprising a holdover oscillator, timing circuitry coupled to the holdover oscillator and configured to receive the GPS traceable timing signal and to calculate a correction factor for the holdover oscillator, and a non-volatile memory coupled to the timing circuitry, wherein the timing circuitry is configured to store the correction factor on the non-volatile memory.