I really need some help with the specific assignment. The user inputs birth data (YYYY MM DD) and the program tells you how old you are in days :
The outprint in co
Use the DateFormat class which you can utilize the .parse() on the input. Which gives you a Date class which then has .getTime() which returns the number of milliseconds. Then create a new Date class and subtract the .getTime() milliseconds. Convert to Days.
Date birth = DateFormat.parse(inputString);
Date now = new Date();
long diff = now.getTime() - now.getTime();
int days = ((((diff / 1000) / 60) / 60) / 24)
EDIT: According to the code you listed below, you should just be able to do
Scanner input=new Scanner(System.in);
System.out.print ("Enter birth date (yyyy/mm/dd): ");
String yourBirthDay=input.nextLine();
Date birth = DateFormat.parse(yourBirthDay);
Date now = new Date();
long diff = now.getTime() - now.getTime();
int days = ((((diff / 1000) / 60) / 60) / 24)