public static void main(String[] args) throws IOException {

Random randomNumY = new Random();

int yearNum = randomNumY.nextInt(10001);

int numDays = 0;

Random randomNumM = new Random();

int monthNum = randomNumM.nextInt(13);

switch (monthNum) {

case 1: case 3: case 5: case 7: case 8: case 10: case 12:

numDays = 31; break;

case 4: case 6: case 9: case 11:

numDays = 30; break;

case 2:

if (((yearNum % 4 == 0) && !(yearNum % 100 == 0))||(yearNum % 400 == 0))

numDays = 29;

else

numDays = 28;

break;

default:

System.out.println("Oops!! Invalid month, please run again.");

break;

}

System.out.println("In year " + yearNum + " month #"+ monthNum + " has/had " + numDays + " days");

}