Something like this
String myTime = "14:10";
SimpleDateFormat df = new SimpleDateFormat("HH:mm");
Date d = df.parse(myTime);
Calendar cal = Calendar.getInstance();
cal.setTime(d);
cal.add(Calendar.MINUTE, 10);
String newTime = df.format(cal.getTime());
As a fair warning there might be some problems if daylight savings time is involved in this 10 minute period.