Precisely, your time in NetStation time (in this scenario 2xxxxxxx) is the critical value. That’s the time saved in your eeg file for when the event occurred.
Yes, your numbers could be 3749598377475850827 in PsychoPy and 3 in NetStation. So long as the subsequent events show an equal difference it doesn’t matter. The only caveat there is that you want to make sure your NetStation times are stored properly in your eeg file after you end a recording. Test your scripts heavily before collecting real data.
On a side note, the added benefit of using this system is that you can specify times that are different from your time of sending events. E.g.- if you wanted to send an event after a response was made such that your timestamp ends up at the start of your previous trial, you just need to provide your time from when the previous trial started. That’s the real beauty of this system over parallel port triggers (which are great for precision, but not for information). Although 999 out of 1000 people use PyNetstation as a simple triggering system so don’t worry if that’s your intention.