Can you please tell me why the 12hr clock shows am when it should show pm and doesn't go up to 12?

#include using namespace std; // Class declaration class _24HourTime; // Definition of enum which tracks AM or PM in 12 hour clock enum AMPM { AM , PM }ampm; // Abstract class used to track time class Time { public: int hour; int minute; int second; virtual void addOneHour() = 0; virtual void addOneMinute() = 0; virtual void addOneSecond() = 0; }; // _12HourTime class which inherits the Time class class _12HourTime : public Time { // Method to manage the 12 hour time public: _12HourTime(int h , int m , int s) { hour = h; minute = m; second = s; ampm = AM; } // Method to add one hour to the clock void addOneHour() { if(hour == 11) { hour = 0; ampm = ampm == AM ? PM : AM; }else { hour += 1; } } // Method to add one minute to the clock void addOneMinute() { if(minute == 59) { minute = 0; addOneHour(); }else { minute += 1; } } // Method to add one second to the clock void addOneSecond() { if(second == 59) { second = 0; addOneMinute(); }else { second += 1; } } // Declare friend to give proper access friend void displayTime(const _12HourTime& ,const _24HourTime&); }; // _24HourTime class which inherits the Time class class _24HourTime : public Time { // Method to manage 24 hour time public: _24HourTime(int h , int m , int s) { hour = h; minute = m; second = s; } // Method to add one hour to the clock void addOneHour() { if(hour == 23) { hour = 0; }else { hour += 1; } } // Method to add one minute to the clock void addOneMinute() { if(minute == 59) { minute = 0; addOneHour(); }else { minute += 1; } } // Method to add one second to the clock void addOneSecond() { if(second == 59) { second = 0; addOneMinute(); }else { second += 1; } } // Declaring friend to give proper access friend void displayTime(const _12HourTime& ,const _24HourTime&); }; // Displaytime will be able to display time with appropriate formatting void displayTime(const _12HourTime& time12 ,const _24HourTime& time24) { cout << "*************************** *************************** "; cout << "* 12-Hour Clock * * 24-Hour Clock * "; cout << "* "; if(time12.hour < 10) cout << "0"; cout << time12.hour << ":"; if(time12.minute < 10 ) cout << "0" ; cout << time12.minute << ":"; if(time12.second < 10) cout << "0"; cout << time12.second; if(ampm == AM ) cout << " A M"; else cout << " P M"; cout << " * * "; if(time24.hour < 10) cout << "0"; cout << time24.hour << ":"; if(time24.minute < 10 ) cout << "0" ; cout << time24.minute << ":"; if(time24.second < 10) cout << "0"; cout << time24.second; cout << " * "; cout << "*************************** *************************** "; } // Create the interface void displayMenu() { cout << "*************************** "; cout << "* 1 - Add One Hour * "; cout << "* 2 - Add One Minute * "; cout << "* 3 - Add One Second * "; cout << "* 4 - Exit Program * "; cout << "*************************** "; } // Declare main method int main() { //Create clocks _12HourTime time_12_Clock(11 , 59 , 59 ); _24HourTime time_24_Clock(23,59,59); displayTime(time_12_Clock , time_24_Clock); while(true) { displayMenu(); int choice; cin >> choice; // Add interface functionality switch (choice) { case 1: time_12_Clock.addOneHour(); time_24_Clock.addOneHour(); displayTime(time_12_Clock , time_24_Clock); break; case 2: time_12_Clock.addOneMinute(); time_24_Clock.addOneMinute(); displayTime(time_12_Clock , time_24_Clock); break; case 3: time_12_Clock.addOneSecond(); time_24_Clock.addOneSecond(); displayTime(time_12_Clock , time_24_Clock); break; case 4: cout << "Now exiting program."; exit(1); break; default: // Put an error check in place cout << "Error: Invalid choice. Please try again. "; break; } } }