DateTime serialization/deserialization being effected by time zones incorrectly.

[rshuck]

If in postman I send

curl --location --request POST 'http://localhost:8080/api' \
--header 'Content-Type: application/json' \
--data-raw '{
    "DateIn": "2021-10-30T09:47:58.777Z",
    "DateIn2": "2021-10-31T09:47:58.777Z"
}'

I receive back

{
    "DateIn": "2021-10-30T10:47:58.777+01:00",
    "DateIn2": "2021-10-31T09:47:58.777Z"
}

In the attached example you can see that on serialize/deserialize the DateIn field is begin adjusted by the timezone.
The timezone which effected this is BST and ended 31 Oct. If I send a datetime after this then the timezone offset is not added.

I understand that to reproduce this issue you would have to have your windows regional settings to be a place where you implement a daylight savings time.

SetTest.zip