A method of automatically aligning data measured by a number, n, of monitoring devices (128, 130) in a power monitoring system (102; 120), the monitoring devices (128, 130) being connected to an electrical grid, the method comprising: receiving from each of said monitoring devices respective signal data representing at least frequency variations associated with a voltage signal measured by respective ones of said monitoring devices, said monitoring devices including a reference monitoring device and a second monitoring device, each of the monitoring devices including a cycle counter storing a cycle count of the voltage signal measured by the respective monitoring device, wherein the cycle count is sequentially iterated with each positive or negative, respectively, voltage signal zero-crossing; correlating said signal data from said reference monitoring device with said signal data from said second monitoring device to determine a reference cycle count, M i, associated with said reference monitoring device corresponding to a maximum correlation coefficient and a second cycle count, M j, associated with said second monitoring device corresponding to said maximum correlation coefficient; automatically calculating a direct cycle count offset, M ij, as a difference between said reference cycle count, M i, and said second cycle count, M j, M ij being calculated as M i - M j, and storing said direct cycle count offset in a direct cycle count offset matrix; automatically calculating at least one indirect cycle count offset, corresponding to the direct cycle count offset M ij, as a function of at least M k and at least one of 2 to n-1 direct cycle count offsets by calculating the difference between the respective 2 to n-1 direct cycle count offsets to indirectly derive a cycle count offset for the reference monitoring device and the second monitoring device, said M k being a cycle count associated with a monitoring device of said n monitoring devices other than said reference monitoring device and other than said second monitoring device, wherein an indirect cycle count offset M ij from 2 direct cycle count offsets is calculated as a function of M k according to M ij = M ik - M jk, where k ≠ i ≠ j and 1 ≤ k s n; responsive to said direct cycle count offset differing from said at least one indirect cycle count offset, producing a modified direct cycle count offset equal to said at least one indirect cycle count offset; and communicating said modified direct cycle count offset to said reference monitoring device or to said second monitoring device to cause said reference monitoring device or said second monitoring device to adjust the cycle counter in said reference monitoring device or in said second monitoring device by a value corresponding to said modified direct cycle count offset. receiving from each of said monitoring devices respective signal data representing at least frequency variations associated with a voltage signal measured by respective ones of said monitoring devices, said monitoring devices including a reference monitoring device and a second monitoring device, each of the monitoring devices including a cycle counter storing a cycle count of the voltage signal measured by the respective monitoring device, wherein the cycle count is sequentially iterated with each positive or negative, respectively, voltage signal zero-crossing; correlating said signal data from said reference monitoring device with said signal data from said second monitoring device to determine a reference cycle count, M i, associated with said reference monitoring device corresponding to a maximum correlation coefficient and a second cycle count, M j, associated with said second monitoring device corresponding to said maximum correlation coefficient; automatically calculating a direct cycle count offset, M ij, as a difference between said reference cycle count, M i, and said second cycle count, M j, M ij being calculated as M i - M j, and storing said direct cycle count offset in a direct cycle count offset matrix; automatically calculating at least one indirect cycle count offset, corresponding to the direct cycle count offset M ij, as a function of at least M k and at least one of 2 to n-1 direct cycle count offsets by calculating the difference between the respective 2 to n-1 direct cycle count offsets to indirectly derive a cycle count offset for the reference monitoring device and the second monitoring device, said M k being a cycle count associated with a monitoring device of said n monitoring devices other than said reference monitoring device and other than said second monitoring device, wherein an indirect cycle count offset M ij from 2 direct cycle count offsets is calculated as a function of M k according to M ij = M ik - M jk, where k ≠ i ≠ j and 1 ≤ k s n; responsive to said direct cycle count offset differing from said at least one indirect cycle count offset, producing a modified direct cycle count offset equal to said at least one indirect cycle count offset; and communicating said modified direct cycle count offset to said reference monitoring device or to said second monitoring device to cause said reference monitoring device or said second monitoring device to adjust the cycle counter in said reference monitoring device or in said second monitoring device by a value corresponding to said modified direct cycle count offset.