Just found this while tinkering. If anyone else could test, I'd appreciate it.
Steps to recreate:
- Add record via form in interfaces
- Make sure the form submission has a datetime field, and set that field's default value to Current Time.
- Toggle off 'Allow users to edit this field'.
- Submit form
When the record is created, the date field will have 24 hours added to it.
I originally thought it had something to do with my timezone settings and GMT, but when I toggle on 'Allow users to edit this field', the 24 hours is not added to the date field on record creation.
I have a video here that shows it happening to me.