[N1QL] DATE_FORMAT_STR does not return expression in given format

SELECT DATE_FORMAT_STR("2006-01-02 15:04:05+07:00", "2006-01-02 15:04:05Z07:00");

{

    "requestID": "c85a4243-731f-41a3-9be0-55f80a074da9",

    "clientContextID": "40b15863-08bc-4840-81c7-3a8122400435",

    "signature": {

        "$1": "string"

    },

    "results": [

        {

            "$1": "2006-01-02T15:04:05+07:00"

        }

    ],

    "status": "success",

    "metrics": {

        "elapsedTime": "522.732µs",

        "executionTime": "491.719µs",

        "resultCount": 1,

        "resultSize": 57

    }

}