Hi
Date and Calendar are different class that provide different methods in each other. Better to you, will be using GregorianCalendar class, the class is not abstract like Calendar class, but is a subclass of Calendar.
GregorianCalendar object has many different methods to manipulate the date, time.
You can format the myCalendar object in the same style as Date object, by SimpleDateFormat object.
Try to make in pure Java, a few examples, using GregorianCalendar class.
Bye. Sorry for my english, I'm still learning.