intMain(5)

#include <iostream>
#include <iomanip>
#include <ctime>
#include <cstring>
#include <stdlib.h> //for exit() function
#include <fstream>  //for creating text file
using namespace std;

int total = 0;
int bookingNo = 0;

class Reservation{
private:
  int bookingNo;
  string name;
  int phoneNo;
  int paxNo;
  int day;
  int month;
  int year;
  int time;
  int date;
  long dateAndTime;
public:
  Reservation(){
    bookingNo = 1;
    name = "Tan Phit Huan";
    phoneNo = 0123456777;
    paxNo = 1;
    day = 1;
    month = 1;
    year = 2019;
    time = 1500;
    date = 20190101;
    dateAndTime = 201910201649;
  }
  Reservation(int bNo, string na, int phNo, int pxNo, int d, int mon, int y, int t,int da, long dNt){
    bookingNo = bNo;
    name = na;
    phoneNo = phNo;
    paxNo = pxNo;
    day = d;
    month = mon;
    year = y;
    time = t;
    date = da;
    dateAndTime =dNt;
  }
  void setBookingNo(int bNo){
    bookingNo = bNo;
  }
  int getBookingNo(){
    return bookingNo;
  }
  void setName(string na){
    name = na;
  }
  string getName(){
    return name;
  }
  void setPhoneNo(int phNo){
    phoneNo = phNo;
  }
  int getPhoneNo(){
    return phoneNo;
  }
  void setPaxNo(int pxNo){
    paxNo = pxNo;
  }
  int getPaxNo(){
    return paxNo;
  }
  void setDay(int d){
    day = d;
  }
  int getDay(){
    return day;
  }
  void setMonth(int m){
    month = m;
  }
  int getMonth(){
    return month;
  }
  void setYear(int y){
      year = y;
  }
  int getYear(){
    return year;
  }
  void setTime(int t){
    time = t;
  }
  int getTime(){
    return time;
  }
  void setDate(int da){
    date = da;
  }
  int getDate(){
    return date;
  }
  void setDateAndTime(long dNt){
    dateAndTime = dNt;
  }
  long getDateAndTime(){
    return dateAndTime;
  }
};

class linklist{
private:
  struct node{
    Reservation info;
    node *link;
  }*head;

public:
  linklist(){
    head=NULL;
  }

  void InsNewNode(int bNo, string na, int phNo, int pxNo, int d, int mon, int y, int t, long dNt){
    node*newNode = new node;
    node*p,*q = head;
    newNode -> info.setBookingNo(bNo);
    newNode -> info.setName(na);
    newNode -> info.setPhoneNo(phNo);
    newNode -> info.setPaxNo(pxNo);
    newNode -> info.setDay(d);
    newNode -> info.setMonth(mon);
    newNode -> info.setYear(y);
    newNode -> info.setTime(t);
    newNode -> info.setDateAndTime(dNt);

    //If no records
    if (head == NULL){
      head = newNode;
      return;
    }

    //Insert at the start of list
    if (head -> info.getDateAndTime() > newNode -> info.getDateAndTime()){
      newNode -> link = head;
      head = newNode;
      return;
    }

    while(q->info.getDateAndTime() < newNode -> info.getDateAndTime() && q->link != NULL){
      p = q;
      q = q->link;
    }
    //Insert at the end of the list
    if(q == NULL){
      q = newNode;
      newNode-> link = NULL;
      return;
    //Insert in the middle of the list
    }else{
      p = q;
      q = q->link;
      p->link = newNode;
      newNode-> link = q;
      return;
    }
  }

  void deleteNode(int bNo){
    node *current;
    current = head;
    while (current != NULL){
      if(bNo == current->info.getBookingNo()){
        if(current == head){
          node*temp = head;
          head = head -> link;
          delete temp;

        }else if(current->link == NULL){
          node*p, *q = head;
          while(q -> link != NULL){
            p = q;
            q = q -> link;
          }
          p->link = NULL;
          delete q;

        }else{
          node*p, *q = head;
          while(q -> info.getBookingNo() != bNo){
            p = q;
            q = q -> link;
          }
          p -> link = q ->link;
          delete q;
        }
      }
      current = current->link;
    }
    total--;
  }

  void PrintList(){
    node *current;
    current = head;
    cout<<setfill(' ')<<setw(5)<<"| No. "
    <<left<<setw(30)<<"Name"
    <<setw(5)<<"Phone No."
    <<right<<setw(16)<<"Pax No."
    <<setw(10)<<"Date"
    <<setw(16)<<"Time |"<<endl
    <<"|"<<right<<setfill('=')<<setw(86)<<"|"<<endl;

    while (current != NULL){
      cout<<"| "<<setfill(' ')<<current->info.getBookingNo()<<"   "
      <<left<<setw(30)<< current->info.getName()
      <<right<<setw(10)<<setfill('0')<< current->info.getPhoneNo()
      <<setw(12)<<setfill(' ')<< current->info.getPaxNo()<<setw(6)<<setfill(' ')<<" "
      <<setw(2)<<setfill('0')<< current->info.getDay() <<"/"<<setw(2)<<setfill('0')<< current->info.getMonth() <<"/"<<setw(4)<<setfill('0')<< current->info.getYear()<<setw(7)<<setfill(' ')<<" "
      <<setw(4)<<setfill('0')<< current->info.getTime() <<" |"<<endl;
      current = current->link;
    }
    cout<<endl;
  }

  void PrintBookingNoRecords(int bNo){
    node *current;
    current = head;
    cout<<setfill(' ')<<setw(5)<<"| No. "
    <<left<<setw(30)<<"Name"
    <<setw(5)<<"Phone No."
    <<right<<setw(16)<<"Pax No."
    <<setw(10)<<"Date"
    <<setw(16)<<"Time |"<<endl
    <<"|"<<right<<setfill('=')<<setw(86)<<"|"<<endl;

    while (current != NULL){
      //If there is any reservation with the same name
      if(bNo == current->info.getBookingNo()){
        cout<<"| "<<setfill(' ')<<current->info.getBookingNo()<<"   "
        <<left<<setw(30)<< current->info.getName()
        <<right<<setw(10)<<setfill('0')<< current->info.getPhoneNo()
        <<setw(12)<<setfill(' ')<< current->info.getPaxNo()<<setw(6)<<setfill(' ')<<" "
        <<setw(2)<<setfill('0')<< current->info.getDay() <<"/"<<setw(2)<<setfill('0')<< current->info.getMonth() <<"/"<<setw(4)<<setfill('0')<< current->info.getYear()<<setw(7)<<setfill(' ')<<" "
        <<setw(4)<<setfill('0')<< current->info.getTime() <<" |"<<endl;
      }
      current = current->link;
    }
    cout<<endl;
  }

  void PrintNameRecords(string name){
    node *current;
    current = head;
    cout<<setfill(' ')<<setw(5)<<"| No. "
    <<left<<setw(30)<<"Name"
    <<setw(5)<<"Phone No."
    <<right<<setw(16)<<"Pax No."
    <<setw(10)<<"Date"
    <<setw(16)<<"Time |"<<endl
    <<"|"<<right<<setfill('=')<<setw(86)<<"|"<<endl;

    while (current != NULL){
      //If there is any reservation with the same name
      if(name == current->info.getName()){
        cout<<"| "<<setfill(' ')<<current->info.getBookingNo()<<"   "
        <<left<<setw(30)<< current->info.getName()
        <<right<<setw(10)<<setfill('0')<< current->info.getPhoneNo()
        <<setw(12)<<setfill(' ')<< current->info.getPaxNo()<<setw(6)<<setfill(' ')<<" "
        <<setw(2)<<setfill('0')<< current->info.getDay() <<"/"<<setw(2)<<setfill('0')<< current->info.getMonth() <<"/"<<setw(4)<<setfill('0')<< current->info.getYear()<<setw(7)<<setfill(' ')<<" "
        <<setw(4)<<setfill('0')<< current->info.getTime() <<" |"<<endl;
      }
      current = current->link;
    }
    cout<<endl;
  }

  void PrintDateRecords(int date){
    node *current;
    current = head;
    cout<<setfill(' ')<<setw(5)<<"| No. "
    <<left<<setw(30)<<"Name"
    <<setw(5)<<"Phone No."
    <<right<<setw(16)<<"Pax No."
    <<setw(10)<<"Date"
    <<setw(16)<<"Time |"<<endl
    <<"|"<<right<<setfill('=')<<setw(86)<<"|"<<endl;

    while (current != NULL){
      //If there is any reservation with the same date
      if(date == current->info.getDate()){
        cout<<"| "<<setfill(' ')<<current->info.getBookingNo()<<"   "
        <<left<<setw(30)<< current->info.getName()
        <<right<<setw(10)<<setfill('0')<< current->info.getPhoneNo()
        <<setw(12)<<setfill(' ')<< current->info.getPaxNo()<<setw(6)<<setfill(' ')<<" "
        <<setw(2)<<setfill('0')<< current->info.getDay() <<"/"<<setw(2)<<setfill('0')<< current->info.getMonth() <<"/"<<setw(4)<<setfill('0')<< current->info.getYear()<<setw(7)<<setfill(' ')<<" "
        <<setw(4)<<setfill('0')<< current->info.getTime() <<" |"<<endl;
      }
      current = current->link;
    }
    cout<<endl;
  }

  void PrintListTextFile(){
    string fileName;
    int count = 0;
    cout << "---------------=CREATE TEXT FILE=---------------" << endl;
    //Create file with the file name user entered
    cout << "Enter file name: ";
    cin >> fileName;
    cout << "Your .txt file can be found in the same folder where your .cpp file is saved." << endl;
    fileName = fileName + ".txt";

    //output to .txt file
    ofstream file(fileName.c_str());

    if (file.is_open()) {
      //output all the reservation records
      node *current;
      current = head;
      file<<setfill(' ')<<setw(5)<<"| No. "
      <<left<<setw(30)<<"Name"
      <<setw(5)<<"Phone No."
      <<right<<setw(16)<<"Pax No."
      <<setw(10)<<"Date"
      <<setw(16)<<"Time |"<<endl
      <<"|"<<right<<setfill('=')<<setw(86)<<"|"<<endl;

      while (current != NULL){
        count++;
        file<<"| "<<setfill(' ')<<count<<"   "
        <<left<<setw(30)<< current->info.getName()
        <<right<<setw(10)<<setfill('0')<< current->info.getPhoneNo()
        <<setw(12)<<setfill(' ')<< current->info.getPaxNo()<<setw(6)<<setfill(' ')<<" "
        <<setw(2)<<setfill('0')<< current->info.getDay() <<"/"<<setw(2)<<setfill('0')<< current->info.getMonth() <<"/"<<setw(4)<<setfill('0')<< current->info.getYear()<<setw(7)<<setfill(' ')<<" "
        <<setw(4)<<setfill('0')<< current->info.getTime() <<" |"<<endl;
        current = current->link;
      }
      file.close(); //close file
    }
  }

  bool checker(int bNo){
    node *current;
    current = head;
    while(current != NULL){
      if(bNo == current->info.getBookingNo()){
        return true;
      }
      current = current->link;
    }
    return false;
  }
};

linklist RList;
void addRecord();
void updateRecord();
void deleteRecord();
void viewRecord();
void createTextFile();
bool checkYear();
bool checkMonth();


int main() {
  char choice;
  cout << "===============RESTAURANT RESERVATION SYSTEM===============" << endl;
  cout << "Please enter your selection" << endl <<
    "1. Add Reservation Records" << endl <<
    "2. Update Reservation Records" << endl <<
    "3. Delete Reservation Records" << endl <<
    "4. View Reservation Records  " << endl <<
    "5. Create text file" << endl <<
    "6. Exit" << endl;

  cout << "Choice: ";
  cin >> choice;
  cin.clear();
  cin.ignore(1, '\n');
  system("CLS");

  switch (choice) {
  //Add Records
  case '1':
    addRecord();
    break;

  //Update Records
  case '2':
    if (total == 0) {
      cout << "No reservation records available." << endl;
      main();
    }
    updateRecord();

    break;

  //Delete Records
  case '3':
    if (total == 0) {
      cout << "No reservation records available." << endl;
      main();
    }
    deleteRecord();

    break;

  //View Reservation Records
  case '4':
    if (total == 0) {
      cout << "No reservation records available." << endl;
      main();
    }
    viewRecord();
    break;

  //Create Text File
  case '5':
    if (total == 0) {
      cout << "No reservation records available." << endl;
      main();
    }
    createTextFile();
    break;

  case '6':
    exit(1);
    break;

  default:
    cout << choice << " is not valid choice" << endl;
    main();
  }

  return 0;
}

bool checkName(string name);
bool checkYear(int year);
bool checkMonth(int month, int year);
bool checkDay(int day, int month, int year);
bool checkTime(int time, int day, int month, int year);

//OPTION 1 : Add Reservation Records
void addRecord(){
  string name;
  int phoneNo, paxNo, day, month, year, time;
  long dateAndTime;
  int length;
  int correct = 1;
  cout << "-----------------=ADD RECORD=-------------------" << endl;

  do{
    cout<<"Enter name : ";
    getline(cin, name);
  }while(!checkName(name));

  cout<<endl<<"Enter phone number (e.g : 0123456789) : ";
  cin>>phoneNo;

  correct = 1;
  while (correct == 1){
    length = to_string(phoneNo).length();
    if (cin.fail() || phoneNo<0 || length>11){
      cin.clear();
      cin.ignore();
      cout << "Invalid input! Enter positive numbers (maximum 11 digits)!" << endl<<endl;
      cout<< "Enter phone number (e.g : 0123456789) : ";
      cin >> phoneNo;
    }else{
        correct = 0;
    }
  }

  correct = 1;
  cout<<endl<<"Enter number of pax (maximum : 50) : ";
  cin>>paxNo;

  while (correct == 1){
    if (cin.fail() || paxNo<0 || paxNo > 50){
      cin.clear();
      cin.ignore();
      cout << "Invalid input! Enter positive numbers (maximum : 50)!" << endl<<endl;
      cout<< "Enter number of pax (maximum : 50) : ";
      cin >> paxNo;
    }else{
        correct = 0;
    }
  }

  correct = 1;
  do{
    cout<<endl<<"Enter year (e.g : 2019): ";
    cin>>year;
    while (correct == 1){
      if (cin.fail() || year > 2021){
        cin.clear();
        cin.ignore();
        cout << "Invalid input! Enter numbers (maximum year is 2021)!" << endl<<endl;
        cout<< "Enter year (e.g : 2019) : ";
        cin >> year;
      }else{
          correct = 0;
      }
    }
  }while(!checkYear(year));

  correct = 1;
  do{
    cout<<endl<<"Enter month (e.g : January = 1) : ";
    cin>>month;
    while (correct == 1){
      if (cin.fail()){
        cin.clear();
        cin.ignore();
        cout << "Invalid input! Enter numbers!" << endl<<endl;
        cout<< "Enter month (e.g : January = 1) : ";
        cin >> month;
      }else{
          correct = 0;
      }
    }
  }while(!checkMonth(month, year));

  correct = 1;
  do{
    cout<<endl<<"Enter day : ";
    cin>>day;
    while (correct == 1){
      if (cin.fail()){
        cin.clear();
        cin.ignore();
        cout << "Invalid input! Enter numbers!" << endl<<endl;
        cout<< "Enter day : ";
        cin >> day;
      }else{
          correct = 0;
      }
    }
  }while(!checkDay(day, month, year));

  do{
    cout<<endl<<"Enter time in 24hr format (e.g : 3.30pm = 1530) : ";
    cin>>time;
    while (correct == 1){
      if (cin.fail()){
        cin.clear();
        cin.ignore();
        cout << "Invalid input! Enter positive numbers (maximum 4 digits)!" << endl<<endl;
        cout<< "Enter time in 24hr format (e.g : 3.30pm = 1530) : ";
        cin >> time;
      }else{
          correct = 0;
      }
    }
  }while(!checkTime(time, day, month, year));

  bookingNo++;
  cout<<endl<<"Booking Number : "<<bookingNo<<endl;

  //for inserting the node in order according to date and time
  dateAndTime = year*100000000 + month*1000000 + day*10000 + time;

  RList.InsNewNode(bookingNo, name, phoneNo, paxNo, day, month, year, time, dateAndTime);
  total++;
  cin.clear();
  cin.ignore(1000, '\n');
  cout << "Press enter to continue . . .";
  getchar();
  system("CLS");
  main();
}

//OPTION 2 : Update Reservation Records
void updateRecord(){
  string name;
  int bNo, phoneNo, paxNo, day, month, year, time;
  long dateAndTime;
  int length;
  int correct = 1;
  cout << "----------------=UPDATE RECORD=-----------------" << endl;
  cout<<"Enter 0 to return to main menu."<<endl;
  cout << "Enter Booking Number : ";
  cin >> bNo;
  if(bNo == 0){
    main();
  }

  if(RList.checker(bNo)){
    cin.clear();
    cin.ignore(1000, '\n');
    cout<<"Enter name : ";
    getline(cin, name);

    cout<<endl<<"Enter phone number (e.g : 0123456789) : ";
    cin>>phoneNo;

    correct = 1;
    while (correct == 1){
      length = to_string(phoneNo).length();
      if (cin.fail() || phoneNo<0 || length>11){
        cin.clear();
        cin.ignore();
        cout << "Invalid input! Enter positive numbers (maximum 11 digits)!" << endl<<endl;
        cout<< "Enter phone number (e.g : 0123456789) : ";
        cin >> phoneNo;
      }else{
          correct = 0;
      }
    }

    correct = 1;
    cout<<endl<<"Enter number of pax (maximum : 50) : ";
    cin>>paxNo;

    while (correct == 1){
      if (cin.fail() || paxNo<0 || paxNo > 50){
        cin.clear();
        cin.ignore();
        cout << "Invalid input! Enter positive numbers (maximum : 50)!" << endl<<endl;
        cout<< "Enter number of pax (maximum : 50) : ";
        cin >> paxNo;
      }else{
          correct = 0;
      }
    }

    correct = 1;
    do{
      cout<<endl<<"Enter year (e.g : 2019): ";
      cin>>year;
      while (correct == 1){
        if (cin.fail() || year > 2021){
          cin.clear();
          cin.ignore();
          cout << "Invalid input! Enter numbers (maximum year is 2021)!" << endl<<endl;
          cout<< "Enter year (e.g : 2019) : ";
          cin >> year;
        }else{
            correct = 0;
        }
      }
    }while(!checkYear(year));

    correct = 1;
    do{
      cout<<endl<<"Enter month (e.g : January = 1) : ";
      cin>>month;
      while (correct == 1){
        if (cin.fail()){
          cin.clear();
          cin.ignore();
          cout << "Invalid input! Enter numbers!" << endl<<endl;
          cout<< "Enter month (e.g : January = 1) : ";
          cin >> month;
        }else{
            correct = 0;
        }
      }
    }while(!checkMonth(month, year));

    correct = 1;
    do{
      cout<<endl<<"Enter day : ";
      cin>>day;
      while (correct == 1){
        if (cin.fail()){
          cin.clear();
          cin.ignore();
          cout << "Invalid input! Enter numbers!" << endl<<endl;
          cout<< "Enter day : ";
          cin >> day;
        }else{
            correct = 0;
        }
      }
    }while(!checkDay(day, month, year));

    do{
      cout<<endl<<"Enter time in 24hr format (e.g : 3.30pm = 1530) : ";
      cin>>time;
      while (correct == 1){
        if (cin.fail()){
          cin.clear();
          cin.ignore();
          cout << "Invalid input! Enter positive numbers (maximum 4 digits)!" << endl<<endl;
          cout<< "Enter time in 24hr format (e.g : 3.30pm = 1530) : ";
          cin >> time;
        }else{
            correct = 0;
        }
      }
    }while(!checkTime(time, day, month, year));
    //for inserting the node in order
    dateAndTime = year*100000000 + month*1000000 + day*10000 + time;

    RList.InsNewNode(bNo, name, phoneNo, paxNo, day, month, year, time, dateAndTime);
    cout<<"Update process complete."<<endl;
  }else{
    cout<<"No existing record with that booking number."<<endl
    <<"Update process cancelled."<<endl;
  }

  cin.clear();
  cin.ignore(1000, '\n');
  cout << "Press enter to continue . . .";
  getchar();
  system("CLS");
  main();
}

//OPTION 3 : Delete Reservation Records
void deleteRecord(){
  int  bNo;
  char confirm;
  cout << "----------------=DELETE RECORD=-----------------" << endl;
  cout<<"Enter 0 to return to main menu."<<endl;
  cout<<"Enter Booking Number : ";
  cin>>bNo;
  if(bNo == 0){
    main();
  }
  if(RList.checker(bNo)){
    RList.PrintBookingNoRecords(bNo);
    cout<<"Confirm?(y/n) : ";
    cin>>confirm;

    switch (confirm) {
      case 'y':
        RList.deleteNode(bNo);
        cout<<"Deletion process complete."<<endl;
        break;
      default:
        cout<<"Deletion process cancelled."<<endl;
        main();
    }
  }else{
    cout<<"No existing record with that booking number."<<endl;
  }

  cin.clear();
  cin.ignore(1000, '\n');
  cout << "Press enter to continue . . .";
  getchar();
  system("CLS");
  main();
}

//OPTION 4 : View Reservation Records
void viewRecord(){
  char choice;
  string name;
  int bNo, year, month, day, date;
  cout << "-----------------=VIEW RECORD=------------------" << endl;
  cout << "Please enter your selection" << endl <<
  "1. View All Reservations" << endl <<
  "2. Search by Booking Number"<< endl <<
  "3. Search by Name" << endl<<
  "4. Search by Date"<< endl <<
  "5. Back to Main Menu"<< endl;
  cout << "Choice: ";
  cin >> choice;
  cin.clear();
  cin.ignore(1, '\n');
  system("CLS");

  switch (choice) {
  //View All Reservations
  case '1':
    RList.PrintList();
    break;

  case '2':
    cout<<"Enter Booking Number : ";
    cin>>bNo;
    RList.PrintBookingNoRecords(bNo);
    break;

  //Search by Name
  case '3':
    cout<<"Enter Name : ";
    getline(cin, name);

    RList.PrintNameRecords(name);
    break;

  case '4':
    cout<<"Enter year (e.g : 2019) : ";
    cin>>year;

    cout<<"Enter month (e.g : January = 1) : ";
    cin>>month;

    cout<<"Enter day : ";
    cin>>day;

    date = year*10000 + month*100 + day;

    RList.PrintDateRecords(date);
    break;

  case '5':
    main();
    break;

  default:
    cout << choice << " is not valid choice" << endl;
    viewRecord();
  }

  cout << "Press enter to continue . . .";
  getchar();
  system("CLS");
  main();
}

//OPTION 5 : Create Text File
void createTextFile(){
  RList.PrintListTextFile();
  getchar();
  cout << "-----------------------------------------------------" << endl;

  cout << "Press enter to continue . . .";
  cin.clear();
  cin.ignore(1000, '\n');
  system("CLS");
  main();
}

//for checking whether the name is empty
bool checkName(string name){
  int counter = 0;
  for(int i = 0; i<name.length() ; i++){
    if(name.find_first_not_of(' ') != std::string::npos){
      counter++;
    }
  }

  if(counter == 0){
    cout<<"Invalid Input! Need a name!"<<endl;
    return false;
  }else{
    return true;
  }
}

//for getting the current time
time_t now = time(0);
tm *ltm = localtime(&now);

int currentYear = 1900+ltm->tm_year;
int currentMonth = 1 + ltm->tm_mon;
int currentDay = ltm->tm_mday;
int currentHour = ltm->tm_hour;
int currentMinute = ltm->tm_min;

bool checkYear(int year){
  if(year < currentYear){
    cout<<"Can't go back in time!"<<endl;
    return false;
  }else{
    return true;
  }
}

bool checkMonth(int month, int year){
  if(month < currentMonth && year == currentYear){
    cout<<"Can't go back in time!"<<endl;
    return false;
  }else if(month > 12){
    cout<<"There are only 12 months in a year!"<<endl;
    return false;
  }else{
    return true;
  }
}

bool checkDay(int day, int month, int year){
  if(day < currentDay && month == currentMonth && year == currentYear){
    cout<<"Can't go back in time!"<<endl;
  //even months
  }else if(day <= 0){
    cout<<"Can't go back in time!"<<endl;
  }else if(month%2 == 0){
    // if the month is february
    if(month == 2){
      //february in common year that contain 28 days
      if(year%4 != 0 && day>28){
        cout << "Please key in between the day from 1 to 28"<< endl;
      }
      // february in leap year that contain 29 days
      else if(year%4 == 0 && day>29){
        cout << "Please key in between the day from 1 to 29"<< endl;
      }
      else{
        return true;
      }
    }
    // month that are even with 31 days
    else if(month > 7 && day > 31){
      cout << "Please key in between the day from 1 to 31"<< endl;
    }
    // month that are even  with 30 days
    else if(month < 7 && day > 30){
      cout << "Please key in between the day from 1 to 30"<< endl;
    }
    else{
      return true;
    }

  // month is odd
  }else if(month%2 != 0){
    // month that are odd with 30 days
    if(month>8 && day > 30){
      cout << "Please key in between the day from 1 to 30"<< endl;
    // month that are odd with 31 days
    }else if(month<8 && day > 31){
      cout << "Please key in between the day from 1 to 31"<< endl;
    }else{
      return true;
    }
  }
  else{
    return true;
  }
  return false;
}

bool checkTime(int time, int day, int month, int year){
  int hour = time/100;
  int minute = time - hour*100;

  if(hour > 24){
    cout<<"Only 0 to 24 hours."<<endl;
    return false;
  }else if(hour < currentHour && day == currentDay && month == currentMonth && year == currentYear){
    cout<<"Can't go back in time!"<<endl;
    return false;
  }else{
    return true;
  }

  if(minute > 59){
    cout<<"Only 0 to 59 minutes."<<endl;
  }else if(minute < currentMinute && hour == currentHour && day == currentDay && month == currentMonth && year == currentYear){
    cout<<"Can't go back in time!"<<endl;
  }else{
    return true;
  }
  return false;
}