Here is an example to convert seconds in display time format.

Time.Swift

import Foundation

func formatDuration(_ durationInSeconds: Int) -> String {
    let (hours, secondsAfterHours) = divmod(durationInSeconds, 3600)
    let (minutes, seconds) = divmod(secondsAfterHours, 60)
    return String(format: "%02d:%02d:%02d", hours, minutes, seconds)
}

func divmod(_ numerator: Int,
            _ denominator: Int) -> (quotient: Int, remainder: Int) {
    let quotient = numerator / denominator
    let remainder = numerator % denominator
    return (quotient, remainder)
}

let durationInSeconds = 3661
let formattedDuration = formatDuration(durationInSeconds)
print("Duration: \(formattedDuration)") // Duration: 01:01:01