Accessing the raw value

Enumeration instances with raw values have a handy rawValue property. With the raw values in place, your enumeration has a sense of order and you can calculate the number of months left until winter break:

func monthsUntilWinterBreak(from month: Month) -> Int { return Month.december.rawValue - month.rawValue

}

monthsUntilWinterBreak(from: .april) // 8