Programming Challenge 10.13 - Date Printer

/* Date Printer - This program reads a string from the user containing a
   date in the form mm/dd/yyyy. It prints the date in the form March 12,
    2014. */

#include "Utility.h"

/* Performs various checks to confirm validity of input,
    returns the result */
bool checkDate(string);

/* Determines the correct month name,
   returns the month name */
string months(int);

/* Inserts month, day and year into the date string,
   displays the date */
void printDate(string, int, int);

int main()
{
    int    month = 0,
             day = 0,
            year = 0;
    string date = " ";

    cout << "\n\tDATE PRINTER\n\n"
          << "\tEnter a date in the format 'mm/dd/yyyy' and I will\n"
          << "\tconvert and display it. For example, after entering\n"
          << "\t'01/12/2017', the output will be 'January 12, 2017.'\n\n"
          << "\tPlease enter a date: ";
    getline(cin, date);

    while (checkDate(date) == false)
    {
        if (checkDate(date) == false)
        {
            cout << "\n\tThe date entered is invalid.\n"
                  << "\tPlease enter a date: ";
            getline(cin, date);
        }
    }

    month = stoi(date.substr(0));
    day = stoi(date.substr(3));
    year = stoi(date.substr(6));

    date = months(month);
             printDate(date, day, year);

    pauseSystem();
    return 0;
}

/* **********************************************************
   Definition: checkDate

    This function performs the following checks on the string

        * Correct length of the date string (This is the only
          condition that immediately returns the result in case
          the validity check fails)
        * Existence of delimiting characters '/'
        * Correctness of month, day, year input
        * Determins whether the year is a leap year. Based on
          the result, the month and day input is validated once
          more.

    The result is returned.
   ********************************************************** */

bool checkDate(string date)
{

    bool validDate = true;
    bool isLeapYear = false;
    int  month = 0,
          day = 0,
          year = 0;
    char delimiter = '/';

    if (date.length() < 10)
    {
        return validDate = false;
    }

    if (date.at(2) != delimiter || date.at(5) != delimiter)
    {
        validDate = false;
    }

    month = stoi(date.substr(0));

    if (month < 1 || month > 12)
    {
        validDate = false;
    }
   
    day = stoi(date.substr(3));

    if (day < 1 || day > 31)
    {
        validDate = false;
    }

    year = stoi(date.substr(6));

    if (year < 1 || year > 2100)
    {
        validDate = false;
    }

    if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
    {
        isLeapYear = true;
    }

    if (isLeapYear && month == 2 && day > 29)
    {
        validDate = false;
    }

    if (isLeapYear == false && month == 2 && day > 28)
    {
        validDate = false;
    }

    return validDate;
}

/* **********************************************************
   Definition: months

    This function determines the name of a month, based on the
    integer value passed to it. The name is returned.
   ********************************************************** */

string months(const int month)
{
    const string monthNames[12] = { "January", "February", "March",
                                              "April", "May", "June", "July",
                                              "August", "September", "October",
                                              "November", "December" };

    return monthNames[month-1];
}

/* **********************************************************
   Definition: printDate

    This function accepts a string and two int values as
    arguments. It inserts day and year into the date string,
    and displays the date.
   ********************************************************** */

void printDate(string date, int day, int year)
{
    date.insert(date.length(), " " + to_string(day) + ", " + to_string(year));

    cout << "\n\tYour date is: " << date << endl;
}

Example Output: