Abstract: Methods, apparatus, systems, and articles of manufacture to generate a timestamp are disclosed. Examples disclosed herein generate a correction factor based on a first timestamp and a second timestamp, the first timestamp generated before a first data packet is obtained by ethernet physical coding sublayer (PCS), the second timestamp generated before the first data packet is obtained by a physical ethernet port coupled to the ethernet PCS; and generate a third timestamp for a second data packet based on the correction factor and a fourth timestamp, the fourth timestamp generated by network interface circuitry for the second data packet.