A method and apparatus for synchronizing a local clock value in a wireless receiver receiving a data unit containing synchronization information. The method includes receiving a first data unit containing synchronization information, extracting the synchronization information from the received first data unit, copying a local free-running clock at a known reference point in time relative to the time the first data unit was received to generate a local timestamp; and calculating an offset to the free-running clock using the extracted synchronization information and the local timestamp, the calculating in non real-time, such that the sum of the calculated offset and the value of the free-running clock provides a local clock value that is approximately synchronized in time. The apparatus implementing the method is part of a node of a wireless station, and provides a time synchronization function, typically at the MAC layer.