How to convert a DateComponents-object to a localized string, such as "08:40 PM", without specifying year, month, and day?

I have a "time" (hours and minutes) stored in a DateComponents-object, and I like to convert that to a localized string format such that 08:40 PM, och 20:40, etc.

I now how to display a Date-object (NSDAte) in this way, but to convert 20:40 to a Date I must pretend I know the Year, Month, and Day.

Question: Is it possible to to convert a DateComponents-object to a localized string, such as "08:40 PM", by using TimeZone- and Locale-object, but without specifying the Year, Month, and Day?

You can just get todays components and add the desired time to it. You will also need to specify a calendar:

extension Date {
    var year: Int { Calendar.current.component(.year, from: self) }
    var month: Int { Calendar.current.component(.month, from: self) }
    var day: Int { Calendar.current.component(.day, from: self) }
}

extension DateComponents {
    var todaysDateFromTimeComponents: Date? {
        let today =  Date()
        return DateComponents(calendar: .current,
                              year: today.year,
                              month: today.month,
                              day: today.day,
                              hour: hour,
                              minute: minute)
        .date
    }
}

let date = DateComponents(hour: 20, minute: 40).todaysDateFromTimeComponents // "Feb 1, 2017, 8:40 PM"

If you want to display “date information in a given time zone” you should use DateFormatter to format your date.

extension DateFormatter {
    convenience init(timeStyle: DateFormatter.Style) {
        self.init()
        self.timeStyle = timeStyle
    }
}

extension Date {
    static let shortTimeFormatter = DateFormatter(timeStyle: .short)
    func shortTime(with timeZone: TimeZone) -> String {
        Date.shortTimeFormatter.timeZone = timeZone
        return Date.shortTimeFormatter.string(from: self)
    }
}

date?.shortTime(with: TimeZone(identifier: "GMT")!)   // 10:40 PM +2hs