this is similar to a couple of previous discussions:
- https://forum.inaturalist.org/t/graph-time-sighting-data-on-inat-on-animal-species-pages/5525
- https://forum.inaturalist.org/t/graph-data-for-night-dawn-day-dusk-broken-out-by-month/24494
as others have noted, there’s a data quality issue, since there’s data that is recorded without time or at the wrong time zone / offset.
you’re going to have to do some manual / custom filtering to get data by time of day.