import java.time.Duration; Duration duration = Duration.ofHours(1); Duration duration1 = Duration.ofHours(1); Duration duration2 = Duration.ofMinutes(30); Duration sum = duration1.plus(duration2); Duration difference = duration1.minus(duration2); Duration duration = Duration.ofMinutes(90); long hours = duration.toHours(); long minutes = duration.minusHours(hours).toMinutes(); long seconds = duration.minusHours(hours).minusMinutes(minutes).toSeconds(); String formattedDuration = String.format("%02d:%02d:%02d", hours, minutes, seconds);