See #5886 (comment)

Just opening this to make sure we don't lose track of it.

The docs recommend

"If you want the date field to be visible, but not editable by the user, then set read_only=True and additionally set a default=... argument."

It then says:

"The field will not be writable to the user, but the default value will still be passed through to the validated_data."

This is not true. It will not be passed through to the validated_data.