Java tutorial
import java.time.Duration; import java.time.LocalTime; import java.time.temporal.ChronoUnit; public class Main { public static void main(String[] args) { Duration duration = Duration.between(LocalTime.MIDNIGHT, LocalTime.NOON); System.out.println(duration.getSeconds()); duration = duration.plus(4, ChronoUnit.DAYS); System.out.println(duration.getSeconds()); } }