SimpleDateFormat and a strange warning

Question

This is the part of the code with this "strange" warning:

public void onTick(long millisUntilFinished) {
    tv.setText("" + new SimpleDateFormat("mm:ss").format(new Date( millisUntilFinished)));
}

The warning is that:

To get local formatting use getDateInstance(), getDateTimeInstance(), or getTimeInstance(), or use new SimpleDateFormat(String template, Locale locale) with for example Locale.US for ASCII dates.

It's strange for me because I use SimpleDateFormat so I don't understand the reason why the advice for avoiding the warning is exactly to do what it was ever done. Moreover, I use the same thing in other activity without any warning so I compare completely the two codes and there is no difference that could explain that (the two forementioned activities only differ by some constant names.)

Besides, I want to know if it could imply further problems because my program works fine by the way.

Answer 1

To remove the warning just add Locale.getDefault() as the second argument while instantiating the date format object. Eg.

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss",
                java.util.Locale.getDefault());