func greetingLogic() -> String {

  let hour = Calendar.current.component(.hour, from: Date())

  let NEW_DAY = 0

  let NOON = 12

  let SUNSET = 18

  let MIDNIGHT = 24

  var greetingText = "Hello" // Default greeting text

  switch hour {

  case NEW_DAY..<NOON:

      greetingText = "Good Morning"

  case NOON..<SUNSET:

      greetingText = "Good Afternoon"

  case SUNSET..<MIDNIGHT:

      greetingText = "Good Evening"

  default:

      _ = "Hello"

  }

  return greetingText

}