Date Validation

import java.util.Scanner;

public class Dates
{
    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, yearValid, dayValid;  //true if input from user is valid
        boolean leapYear;       //true if user's year is a leap year

        Scanner scan = new Scanner(System.in);

        //Get integer month, day, and year from user
        System.out.println("Enter month");
        month=scan.nextInt();
        System.out.println("Enter day");
        day=scan.nextInt();
        System.out.println("Enter year");
        year=scan.nextInt();
        //Check to see if month is valid
        monthValid=month<13&&month>0;
        //Check to see if year is valid
        yearValid=year>=1000&&year<2000;
        //Determine whether it's a leap year
        leapYear=year%4==0&&year%100!=0||year%400==0;
        //Determine number of days in month
        if(month==1||month==3||month==5||month==7||month==8||month==10||month==12){
            daysInMonth=31;
        }else if(month==4||month==6||month==9||month==11){
            daysInMonth=30;
        }
        else if(!leapYear&&month==2){
            daysInMonth=28;
        }
        else{
            daysInMonth=29;
        }
        //User number of days in month to check to see if day is valid
        dayValid=day<daysInMonth;
        //Determine whether date is valid and print appropriate message
       if(dayValid&&monthValid&&yearValid){
           System.out.println("Valid");
       }else{
           System.out.println("Nope");
       }
    }
}