This is real easy in Java:

    private DayOfWeek getDayOfWeek(int year, int month, int day) {
        return LocalDate.of(year, month, day).getDayOfWeek();
    }

    @Test
    public void getDayOfWeekTest() {
        assertEquals(DayOfWeek.FRIDAY, getDayOfWeek(2016, 3, 25));
    }

It's a built-in function in Java 8. Under the hood, one can see what it's doing is converting the given date to an `EpochDay`, taking the `floorMod` of that by 7, and then returning the index of the DayOfWeek enum. Basically:

    public enum DayOfWeek { MONDAY, TUESDAY... }

    int dow0 = (int)Math.floorMod(toEpochDay() + 3, 7);
    return ENUMS[dayOfWeek - 1];