WHY Isnt my for loop for my leap year program not working : so our assignment is to make a for loop program and while loop program out of our switch statement program, so i just need to know why my for loop program isnt running and if you want to check my while too , that would be great 

while loop:

    /* 
    * File:   main.cpp
    * Author: Jorge Elias
    *
    * Created on October 22, 2017, 11:53 PM
    */

    #include<cstdlib>
    #include<iostream>
    #include<string>
    #include<iomanip>
    using namespace std;

    /*
     * 
     */
     int main( ) {
         //Assigning the Integers
         int month,days,year;
         //Asking User for inputs
         cout<<"Please enter the Year: ";cin>>year;
         cout<<"Please enter the month (1-12): ";cin>>month;
         //Switch statement to determine how many days there are in a month
         switch(month) {
             case 1:
             case 3:
             case 4:
             case 5:
             case 6:
             case 7:
             case 8:
             case 10:
             case 12:
                cout<<"31 days"<<endl;
                break;            
        case 9:
        case 11:
            cout<<"30 days"<<endl;
            break;
     while(month<0){
            cout<<"INVALID INPUT! Please enter month number between 1-12"<<endl;
            break;
            }

    //Determine if the Year inputed by the User is a Leap Year or not
           case 2:
         
           while(year>0){
           if(year % 100 == 0 && year % 400 == 0)
           {
               cout<<"This is a leap year, 29 days"<<endl;
           }
               else if( year % 100 !=0 && year % 4 == 0) 
               {
                   cout<<"This is a leap year, 29 days"<<endl;
               }
               else
                   cout<<"there are 28 days";
           break;
    }
    }           
    return 0;
     }

for loop:
          * 
     * File:   main.cpp
     * Author: Jorge Elias
     *
     * Created on October 22, 2017, 11:53 PM
     */

     #include<cstdlib>
     #include<iostream>
     #include<string>
     #include<iomanip>
     using namespace std;

     /*
      * 
      */
    int main( ) {
    //Assigning the Integers
    int month,days,year;
    //Asking User for inputs
    cout<<"Please enter the Year: ";cin>>year;
    cout<<"Please enter the month (1-12): ";cin>>month;
    //Switch statement to determine how many days there are in a month
    for(month>1; month<12;){
    switch(month) {
        case 1:
        case 3:
        case 4:
        case 5:
        case 6:
        case 7:
        case 8:
        case 10:
        case 12:
            cout<<"31 days"<<endl;
            break;
        case 9:
        case 11:
            cout<<"30 days"<<endl;
            break;
        for(month<1;month>12;){
            cout<<"INVALID INPUT! Please enter month number between 1-12"<<endl;
            break;
        }
        //Determine if the Year inputed by the User is a Leap Year or not
            case 2:
           for(year % 100 == 0;year % 400 == 0;)
           {
               cout<<"This is a leap year, 29 days"<<endl;
              for( year % 100 !=0; year % 4 == 0;) 
               {
                   cout<<"This is a leap year, 29 days"<<endl;
               }
           for(year >0;)
           {
           cout<<"there are 28 days";
           break;
              }
           }
        }     
        }
    return 0;
       }



