  We performed a detailed study of the timing performance of the LHCb VELO
Timepix3 Telescope with a 180 GeV/c mixed hadron beam at the CERN SPS. A
twofold method was developed to improve the resolution of single-plane time
measurements, resulting in a more precise overall track time measurement. The
first step uses spatial information of reconstructed tracks in combination with
the measured signal charge in the sensor to correct for a mixture of different
effects: variations in charge carrier drift time; variations in signal
induction, which are the result of a non-uniform weighting field in the pixels;
and lastly, timewalk in the analog front-end. The second step corrects for
systematic timing offsets in Timepix3 that vary from -2 ns to 2 ns. By applying
this method, we improved the track time resolution from 438$\,\pm\,$16 ps to
276$\,\pm\,$4 ps.
