anchor.diff:                          47.4593
                         ],
                         "publishedAt": "2017-01-24T06:00:00Z",
  -                      "validFrom": "2017-01-24T06:00:00Z",
  -                      "validUntil": "2017-01-24T23:59:59Z",
  +                      "validFrom": "2017-01-24T00:00:00Z",
  +                      "validUntil": "2017-01-25T00:00:00Z",
                         "period": "PT24H",
                         "airPollutionIndex": 3
                       },
  
positive.code:                         47.4593
                        ],
                        "publishedAt": "2017-01-23T06:00:00Z",
                        "validFrom": "2017-01-23T06:00:00Z",
                        "validUntil": "2017-01-23T23:59:59Z",
                        "period": "PT24H",
                        "airPollutionIndex": 2
                      },
  
negative.code:                         47.4593
                        ],
                        "publishedAt": "2017-01-22T06:00:00Z",
                        "validFrom": "2017-01-22T00:00:00Z",
                        "validUntil": "2017-01-23T00:00:00Z",
                        "period": "PT24H",
                        "airPollutionIndex": 1
                      },
  