Packet formats and associated metering infrastructure for filtering meter reading data that is being transmitted by utility meters are disclosed. In one embodiment, a method is provided of measuring the accuracy of an endpoint clock, such as a utility meter clock, from a remote device configured to capture transmissions that originate from the utility meter. Generally, the method includes synchronizing the time maintained by the utility meter with the time maintained by the remote device. The method receives and decodes a packet that includes a time stamp provided by the utility meter. Then, the method calculates the extent of the inaccuracy of the time stamp in the received packet and determines whether the extent of the inaccuracy satisfies a predetermined threshold.