I know of date formats such as
\"yyyy-mm-dd\" -which displays date in format 2011-02-26
\"yyyy-MMM-dd\"-which displays 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());