android datepicker 18 year old validation

try using the Calendar class.

public void onDateSet(DatePicker view, int year, int month, int day) {
    Calendar userAge = new GregorianCalendar(year,month,day);
    Calendar minAdultAge = new GregorianCalendar();
    minAdultAge.add(Calendar.YEAR, -18);
    if (minAdultAge.before(userAge)) {
        SHOW_ERROR_MESSAGE;
    } 
}

this should do what you want :)

Try this

datePickerDialog.getDatePicker().setMaxDate(System.currentTimeMillis() - 568025136000L);