When I tried to use Date argument while formatting, I could see a runtime exception which is not expected.
import java.util.*;

public class Format {
    public static void main(String[] arg) {
    Formatter formatter = new Formatter(System.out);
    System.out.println(" Welcome to formatting world.. ");
    int ni = 2902;
    formatter.format("%0$-80s Is the argument \n",arg);
    formatter.format("%0$80s Is the argument \n",arg);
    formatter.format("%0$^80s Is the argument \n",arg);
    formatter.format("%mt is month ",new Date());
    }
}
console output.
vishalb:/home/vv145429/tiger/src/formating 65 % java Format Sun Microsystems
 Welcome to formatting world..
Sun Is the argument

      Sun Is the argument

      SUN Is the argument
Exception in thread "main" java.util.UnknownFormatConversionException: Conversion = 'm'
    at java.util.Formatter$FormatSpecifier.<init>(Formatter.java:2370)
    at java.util.Formatter.parse(Formatter.java:2212)
    at java.util.Formatter.format(Formatter.java:2146)
    at java.util.Formatter.format(Formatter.java:2100)
    at Format.main(Format.java:11)