Eyelink 1000 and PsychoPy timestamps

Is anyone using code to reset timers at the beginning of each trial? I’m having to do it during data analysis in R. Because the timestamps are different for each participant, (either because of the time tested is different, for Eyelink, or because of the time it takes one participant to read instructions etc is different, for PsychoPy) and because time accumulates over trials, it makes most sense to set the start time of the timestamp to 0 at the beginning of each trial (so then I can compare pupil dilation over the course of the trial for different trials across participants). While this is easy to do with a simple loop in R, I was wondering if anyone has implemented in their code to just have their data come out this way!