public static void main(String[] args) {
        int month, day, year; //date read in from user
        int daysInMonth; //number of days in month read in

        boolean monthValid = false, yearValid = false, dayValid; //true if input from user is valid
        boolean leapYear = false; //true if user's year is a leap year

        Scanner scan = new Scanner(System.in);

        System.out.print("Enter Month as a number: ");
        month = scan.nextInt();

        System.out.print("Enter in the day:");
        day = scan.nextInt();

        System.out.print("Enter in the year in the 2nd-millennium:");
        year = scan.nextInt();

        //Get integer month, day, and year from user

        if (month >= 1 && month <= 12) {
            monthValid = true; //Check to see if month is valid
        }
        if (year >= 1000 && year <= 1999) {
            yearValid = true; //Check to see if year is valid
        }
        //Determine whether it's a leap year

        if (year % 400 == 0) {
            leapYear = true;
        } else if (year % 4 == 0) {
            if (year % 100 == 0) {
                leapYear = false;
            } else {
                leapYear = true;
            }
        }

        //Determine number of days in month

        daysInMonth = 31;

        if (month == 4 || month == 6 || month == 9 || month == 11) {
            daysInMonth = 30;
        } else {
            if (month == 2 && leapYear == true) {
                daysInMonth = 29;
            } else {
                daysInMonth = 28;
            }
        }

        if (monthValid == false) {
            daysInMonth = 0;
        }

        //User number of days in month to check to see if day is valid

        if (day <= daysInMonth) {
            dayValid = true;
        } else {
            dayValid = false;
        }
        //Determine whether date is valid and print appropriate message
        if (monthValid == true && yearValid == true && dayValid == true) {
            System.out.println("Date is valid.");
            if (leapYear) {
                System.out.println("Is Leap year.");
            }
        } else {
            System.out.println("Date is not valid.");
        }
    }