curl --request GET \
  --url 'https://api.511.org/transit/holidays?api_key='

{
  "Siri": {
    "ServiceDelivery": {
      "DataObjectDelivery": {
        "dataObjects": {
          "ServiceCalendarFrame": {
            "ServiceCalendar": {
              "id": "SF",
              "Name": "Holiday exceptions",
              "operatingPeriods": {
                "UicOperatingPeriod": [
                  {
                    "FromDate": "2026-11-26",
                    "ToDate": "2026-11-26",
                    "Name": "Thanksgiving Day"
                  }
                ]
              }
            }
          }
        }
      }
    }
  }
}