请问这道题如何改正

//3-8程序模板，请在此基础上修改并完善代码，使其具有完善的功能。

#include <iostream>
using  namespace std;

#include <ctime>
#include <cstdlib>

enum Months{JAN=1,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC};


void printDate(Months,int,int);
int validDate(int,int);




int main()
{
    int month=1,day=1,year=1900;

    srand(time(0));

    printDate(month,day,year);
    year=getYear(year);
    getMonth();
    day=getDay();

    if(validDate(month,day,year)==true)
        printDate(month,day,year);

    return 0;
}

int getMonth()
{
    Months myMonth=rand()%12+1;
    return myMonth;
}

int getYear(int aYear)
{
    return rand()%101+1900;
}

void getDay(){return rand()%31+1;}


void printDate(Months month,int day,int year)
{   //改正并完成下面函数
    switch(month)
    {
    case JAN:cout<<"January "<<day<<","<<year<<endl;
    case FEB:cout<<"February "<<day<<","<<year<<endl;
   
    //完成其他情况


    default:cout<<"invalid month\n";
    }
}

bool validDate(int month,int day,int year)
{
    int month,day,year;

    if(year<1900||year>2001)
        return false;
    else if(month<1||month>12)
        return false;
    else if(day<1||day>31)
        return false;
    else if(day==31&&(month==APR||month==JUN||month==SEP||month==NOV))
        return false;
    else if(month==2&&day>28)
        return false;

}