I would not go crazy about putting so much effort into timing stars, you can get your seed with less accurate information as long as you have a lot of information.
I had the dates of three announced meteor showers, two dates when Celeste was there (no info about stars, merely the day she was there), one day with a rainbow this week, logged about three types of weather yesterday accurately (meaning with correct clouds) and then went through my screenshots and added about 10 days of rain/no rain from my screenshots (could not see the clouds) - one entry per day on average.
Even though I did not have realy accurate information there was one seed found and so far it has been spot on for yesterday and today's weather, so it seems I have found the right one. Might TTing to a date with meteor or rainbow and see if it is really correct, but so far it seems to be right.
So before going crazy and writing down shooting stars with minutes/seconds, try to put in simplier data as long as you have the information - if there is nothing found you can still add more information later.