Call your setter methods.
setOpponent(opponent);
in your constructor.
You will need to construct a new date object using your five int params and pass it to your setDate() method.
Calendar class has a compareTo() method.
You can't call Calendar constructor directly but you can get a Calendar object by calling one of the static getInstance() methods, preferably the no param one.
As I don't see a boolean field for A.M./P.M. in your UML, I'm assuming you're using military time (i.e. 0:00 - 23:59) for hours.
If so, then you can use your new Calendar object and call
set(int year, int month, int day, int hourOfDay, int minute);
Note that the you use the value 0 for the month of January and so on up to 11 for December.
Then you can use your Calendar object to call setDate() with it as a parameter.