Is there a date format to display the day of the week in java?

Yep - 'E' does the trick

http://download.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html

Date date = new Date();
DateFormat df = new SimpleDateFormat("yyyy-MM-E");
System.out.println(df.format(date));

This should display 'Tue':

new SimpleDateFormat("EEE").format(new Date());

This should display 'Tuesday':

new SimpleDateFormat("EEEE").format(new Date());

This should display 'T':

new SimpleDateFormat("EEEEE").format(new Date());

So your specific example would be:

new SimpleDateFormat("yyyy-MM-EEE").format(new Date());