Duration duration = Duration.ofSeconds(10); for (int i = 0; i < 1000; i++) { duration = duration.plusSeconds(1); } HashMap<String, Duration> durationCache = new HashMap<>(); Duration duration = Duration.ofMinutes(5); if (durationCache.containsKey("calculatedDuration")) { duration = durationCache.get("calculatedDuration"); } else { // ... durationCache.put("calculatedDuration", duration); } Duration duration = Duration.ofMinutes(5); duration = duration.withSeconds(30); duration = duration.withDays(1);