The Legacy PageConverter generates wrong Block Items.
The field render use the PageService, which makes it right.

I would like use the toHash and fromHash function of the FieldService for a migration.
There it runs in an error, because there the attributes are no DateTime objects:
https://github.com/ezsystems/ezpublish-kernel/blob/6.7/eZ/Publish/Core/FieldType/Page/HashConverter.php#L168