Thread: This code is not giving correct values

I am a beginning self taught programmer. I was thinking this would be a good exercise to get used to program control statements. This is an attempt to write a program that returns the number of days between two dates. Sadly, it give incorrect values and after hours of trying to figure out what is wrong, I was hoping someone would help me. I will accept any form of help and criticism to help me improve. Thank you

public class DaysBetweenDates {
    public static boolean isLeapyear(int year) {//This method will determine if a year is a leap year or not
        boolean isTrue=false;
        if(year%4==0 && year%100!=0) isTrue=true;
        else if(year%400==0)         isTrue=true;
        return isTrue;
    }
    public static int computeDaysLeftInYear(int year1,int month1, int day1) {//This method is supposed to compute the days after the first date in 
                                                                            //the first year
        int daysInYearOne=0;
        switch(month1) {//The purpose of this switch is to get the day remaining in the first month and store them in the variable daysInYearOne
            case 1: 
                daysInYearOne=31-day1;
                break;
            case 2: 
                if(DaysBetweenDates.isLeapyear(year1)) daysInYearOne=29-day1;
                else daysInYearOne=28-day1;
                break;
            case 3: 
                daysInYearOne=31-day1;
                break;
            case 4: 
                daysInYearOne=30-day1;
                break;
            case 5: 
                daysInYearOne=31-day1;
                break;
            case 6: 
                daysInYearOne=30-day1;
                break;
            case 7: 
                daysInYearOne=31-day1;
                break;
            case 8: 
                daysInYearOne=31-day1;
                break;
            case 9: 
                daysInYearOne=30-day1;
                break;
            case 10: 
                daysInYearOne=31-day1;
                break;
            case 11: 
                daysInYearOne=30-day1;
                break;
            default: 
                daysInYearOne=31-day1;
 
 
        }
 
        switch(month1+1) {//This switch is supposed to get the values of the days in the month for the rest of year one stored inside the variable 
            case 2:       //daysInYearOne
                    if(DaysBetweenDates.isLeapyear(year1)) daysInYearOne+=29;
                    else daysInYearOne+=28;
            case 3:
                    daysInYearOne+=31;
            case 4:
                    daysInYearOne+=30;
            case 5:
                    daysInYearOne+=31;
            case 6:
                    daysInYearOne+=30;
            case 7: 
                    daysInYearOne+=31;
            case 8:
                    daysInYearOne+=31;
            case 9:
                    daysInYearOne+=30;
            case 10:
                    daysInYearOne+=31;
            case 11:
                    daysInYearOne+=30;
            default:
                    daysInYearOne+=31;
 
        }
        return daysInYearOne;
    }
 
       public static int computeDaysFromYearsInbetween(int year1, int year2) {//This method is supposed to find the days in the whole years that lie 
           int daysInbetweenYears=0;                                          // between the partial years 
           for(int i=year1+1;i<=year2-1;i++) {
               if(DaysBetweenDates.isLeapyear(i)) daysInbetweenYears+=366;
               else daysInbetweenYears+=365;
           }
 
           return daysInbetweenYears;
       }
 
       public static int computeDaysBeforeDate(int year2, int month2, int day2) {//This method is supposed to find the days in the last year by using 
           int daysInYearTwo=0;                                                 //the first method. I was trying to follow the never repeat yourself principle
           if(DaysBetweenDates.isLeapyear(year2)) daysInYearTwo=366-DaysBetweenDates.computeDaysLeftInYear(year2,month2,day2);
           else                                   daysInYearTwo=365-DaysBetweenDates.computeDaysLeftInYear(year2,month2,day2);
           return daysInYearTwo; 
       }
 
       public static void main(String[] args) {
           int v1=DaysBetweenDates.computeDaysLeftInYear(2012,1,1);
           int v2=DaysBetweenDates.computeDaysFromYearsInbetween(2012,2013);
           int v3=DaysBetweenDates.computeDaysBeforeDate(2013,12,31);
 
           System.out.println( v1+v2+v3);
       }
 
 
}