Swift - Integer conversion to Hours/Minutes/Seconds

Question

Define

func secondsToHoursMinutesSeconds(_ seconds: Int) -> (Int, Int, Int) {
    return (seconds / 3600, (seconds % 3600) / 60, (seconds % 3600) % 60)
}

Use

> secondsToHoursMinutesSeconds(27005)
(7,30,5)

or

let (h,m,s) = secondsToHoursMinutesSeconds(27005)

The above function makes use of Swift tuples to return three values at once. You destructure the tuple using the let (var, ...) syntax or can access individual tuple members, if need be.

If you actually need to print it out with the words Hours etc then use something like this:

func printSecondsToHoursMinutesSeconds(_ seconds: Int) {
  let (h, m, s) = secondsToHoursMinutesSeconds(seconds)
  print ("\(h) Hours, \(m) Minutes, \(s) Seconds")
}

Note that the above implementation of secondsToHoursMinutesSeconds() works for Int arguments. If you want a Double version you'll need to decide what the return values are - could be (Int, Int, Double) or could be (Double, Double, Double). You could try something like:

func secondsToHoursMinutesSeconds(seconds: Double) -> (Double, Double, Double) {
  let (hr,  minf) = modf(seconds / 3600)
  let (min, secf) = modf(60 * minf)
  return (hr, min, 60 * secf)
}

In macOS 10.10+ / iOS 8.0+ (NS)DateComponentsFormatter has been introduced to create a readable string.

It considers the user's locale und language.

let interval = 27005

let formatter = DateComponentsFormatter()
formatter.allowedUnits = [.hour, .minute, .second]
formatter.unitsStyle = .full

let formattedString = formatter.string(from: TimeInterval(interval))!
print(formattedString)

The available unit styles are positional, abbreviated, short, full, spellOut and brief.

For more information please read the documenation.

Building upon Vadian's answer, I wrote an extension that takes a Double (of which TimeInterval is a type alias) and spits out a string formatted as time.

extension Double {
  func asString(style: DateComponentsFormatter.UnitsStyle) -> String {
    let formatter = DateComponentsFormatter()
    formatter.allowedUnits = [.hour, .minute, .second, .nanosecond]
    formatter.unitsStyle = style
    return formatter.string(from: self) ?? ""
  }
}

Here are what the various DateComponentsFormatter.UnitsStyle options look like:

10000.asString(style: .positional)  // 2:46:40
10000.asString(style: .abbreviated) // 2h 46m 40s
10000.asString(style: .short)       // 2 hr, 46 min, 40 sec
10000.asString(style: .full)        // 2 hours, 46 minutes, 40 seconds
10000.asString(style: .spellOut)    // two hours, forty-six minutes, forty seconds
10000.asString(style: .brief)       // 2hr 46min 40sec

Here is a more structured/flexible approach: (Swift 3)

struct StopWatch {

    var totalSeconds: Int

    var years: Int {
        return totalSeconds / 31536000
    }

    var days: Int {
        return (totalSeconds % 31536000) / 86400
    }

    var hours: Int {
        return (totalSeconds % 86400) / 3600
    }

    var minutes: Int {
        return (totalSeconds % 3600) / 60
    }

    var seconds: Int {
        return totalSeconds % 60
    }

    //simplified to what OP wanted
    var hoursMinutesAndSeconds: (hours: Int, minutes: Int, seconds: Int) {
        return (hours, minutes, seconds)
    }
}

let watch = StopWatch(totalSeconds: 27005 + 31536000 + 86400)
print(watch.years) // Prints 1
print(watch.days) // Prints 1
print(watch.hours) // Prints 7
print(watch.minutes) // Prints 30
print(watch.seconds) // Prints 5
print(watch.hoursMinutesAndSeconds) // Prints (7, 30, 5)

Having an approach like this allows the adding of convenience parsing like this:

extension StopWatch {

    var simpleTimeString: String {
        let hoursText = timeText(from: hours)
        let minutesText = timeText(from: minutes)
        let secondsText = timeText(from: seconds)
        return "\(hoursText):\(minutesText):\(secondsText)"
    }

    private func timeText(from number: Int) -> String {
        return number < 10 ? "0\(number)" : "\(number)"
    }
}
print(watch.simpleTimeString) // Prints 07:30:05

It should be noted that purely Integer based approaches don't take leap day/seconds into account. If the use case is dealing with real dates/times Date and Calendar should be used.

I have built a mashup of existing answers to simplify everything and reduce the amount of code needed for Swift 3.

func hmsFrom(seconds: Int, completion: @escaping (_ hours: Int, _ minutes: Int, _ seconds: Int)->()) {

        completion(seconds / 3600, (seconds % 3600) / 60, (seconds % 3600) % 60)

}

func getStringFrom(seconds: Int) -> String {

    return seconds < 10 ? "0\(seconds)" : "\(seconds)"
}

Usage:

var seconds: Int = 100

hmsFrom(seconds: seconds) { hours, minutes, seconds in

    let hours = getStringFrom(seconds: hours)
    let minutes = getStringFrom(seconds: minutes)
    let seconds = getStringFrom(seconds: seconds)

    print("\(hours):\(minutes):\(seconds)")                
}

Prints:

00:01:40

In Swift 5:

    var i = 9897

    func timeString(time: TimeInterval) -> String {
        let hour = Int(time) / 3600
        let minute = Int(time) / 60 % 60
        let second = Int(time) % 60

        // return formated string
        return String(format: "%02i:%02i:%02i", hour, minute, second)
    }

To call function

    timeString(time: TimeInterval(i))

Will return 02:44:57

Swift 5:

extension Int {

    func secondsToTime() -> String {

        let (h,m,s) = (self / 3600, (self % 3600) / 60, (self % 3600) % 60)

        let h_string = h < 10 ? "0\(h)" : "\(h)"
        let m_string =  m < 10 ? "0\(m)" : "\(m)"
        let s_string =  s < 10 ? "0\(s)" : "\(s)"

        return "\(h_string):\(m_string):\(s_string)"
    }
}

Usage:

let seconds : Int = 119
print(seconds.secondsToTime()) // Result = "00:01:59"