How to use java calendar to check whether today is Sunday

I wrote a few lines of code that didn't work Why? Can you explain something?

Calendar date = Calendar.getInstance();

    date.set(2010,03,7);

    if(date.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY)
        System.out.println("OK");

Solution

To avoid errors, you can use the calendar static value of the month, for example:

date.set(2010,Calendar.MARCH,7);