Java tutorial
import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; public class Main { public static void main(String[] args) throws Exception { SimpleDateFormat simpleDateFormat1 = new SimpleDateFormat("yyyy-MM-dd"); Date workDate = simpleDateFormat1.parse("2011-11-27"); Calendar workCalendar = Calendar.getInstance(); workCalendar.setTime(workDate); SimpleDateFormat simpleDateFormat2 = new SimpleDateFormat("HH:mm:ss"); Calendar time = Calendar.getInstance(); time.setTime(simpleDateFormat2.parse("06:00:00")); workCalendar.set(Calendar.HOUR_OF_DAY, time.get(Calendar.HOUR_OF_DAY)); workCalendar.set(Calendar.MINUTE, time.get(Calendar.MINUTE)); workCalendar.set(Calendar.SECOND, time.get(Calendar.SECOND)); Date newWorkDate = workCalendar.getTime(); SimpleDateFormat simpleDateFormat3 = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"); System.out.println(simpleDateFormat3.format(newWorkDate)); } }