OK I have an interesting one here. My friend in Newfoundland (not too far from Ontario) is having some variation of this issue.
She has about 19 casual grade observations due to the date being blank in the app, even though it is present in the JSON via “observed_on_string”.
All of the observations made in 2020 in this list: https://www.inaturalist.org/observations?place_id=any&subview=table&user_id=sarahkristine&verifiable=false
Here is an example: https://www.inaturalist.org/observations/50476010
If you look at the JSON there is an accurate “observed_on_string” and the time zone is wrong in the “time_zone” and “zic_time_zone” fields:
Her images have Newfoundland Daylight Time in the “observed_on_string”: GMT-0230 (GMT-2:30)
But the “time_zone” and “zic_time_zone” say a “Hawaii” / “Pacific/Honolulu”
The location data on the observations is accurate.