core/homeassistant/components/holiday/strings.json

{
  "config": {
    "abort": {
      "already_configured": "Already configured. Only a single configuration for country/province combination possible."
    },
    "step": {
      "user": {
        "data": {
          "country": "Country"
        }
      },
      "province": {
        "data": {
          "province": "Province"
        }
      }
    }
  }
}