Java tutorial
import java.time.Duration; import java.time.LocalTime; import java.time.Period; import java.time.temporal.ChronoUnit; import java.time.temporal.UnsupportedTemporalTypeException; public class Main { public static void main(String[] args) { LocalTime localTime = LocalTime.of(11, 20, 50); System.out.println(localTime.plus(3, ChronoUnit.HOURS)); System.out.println(localTime.plus(Duration.ofDays(3))); //11:20:50 try { System.out.println(localTime.plus(Period.ofDays(3))); } catch (UnsupportedTemporalTypeException e) { e.printStackTrace(); } } }