A method for determining an internal time of a time-sensitive networking (TSN) network card includes generating at least one initial packet with a launch time parameter at a computing device. The computing device sends the at least one initial packet to a TSN network card for transmission and receives a transmit completion signal from the TSN network card confirming that the TSN network card transmitted the at least one initial packet. The computing device determines an approximate current internal time of the TSN network card using the launch time parameter and the received transmit completion signal.