Abstract: A method for changing an activation state of an interruption module for selectively interrupting at least one passive cathodic protection unit from a metallic structure. The method includes enabling a global positioning system (GPS) receiver in data communication with a controller of the interruption module, receiving GPS time via the GPS receiver from at least one global positioning system satellite in data communication therewith, synchronizing a real-time clock time of a real-time clock in data communication with the controller to GPS time, disabling the GPS receiver and changing the activation state of the interruption module if a predetermined activation state change time of the interruption module is between the local real-time clock time and the GPS time.