Accurate timing services are important for effectively operating power grids. Traditionally, supervisory control and data acquisition (SCADA) systems make use of time stamps to quickly identify and respond to faults in the event of incidents. However, with the increasing penetration of renewable energy sources such as solar and wind, the grid has become more susceptible to even minor disturbances. In response, utilities have begun deploying wide-area monitoring systems (WAMS) to monitor real-time voltage and frequency oscillations, which mainly consist of phasor measurement units (PMUs). These systems require a time stamp at every measurement, with a high level of accuracy, which means that the timing services must guarantee 24/7 availability.