SimpleDateFormat returning incorrect day on given date

Question

I was recently doing a question on HackerRank in which I was asked to find the day on a given date. I used SimpleDateFormat to find the day.

Below is my code:

String sd = Integer.toString(day) + "-" + Integer.toString(month) + "-" + Integer.toString(year);
try {
    Date d = new SimpleDateFormat("DD-MM-yyyy").parse(sd);
    SimpleDateFormat sdf = new SimpleDateFormat("EEEE");
    return sdf.format(d).toUpperCase();
} catch (Exception e) {
    return "";
}

The funny thing here is that the above code is printing correct result for today's date i.e. 03/04/2020(Friday) but it is returning incorrect day on 05/08/2015(it should return Wednesday but instead it returns Monday).

Please help me to find the problem.

Thank you.

EDIT I was doing a little mistake that I wanted to use the day of the month, for which dd has to be used. DD represents the day of the year. That solved my problem!

Answer 1

You should be using SimpleDateFormat("dd-MM-yyyy").

DD is for day in year, like there are 365 days in a year.