checking the user input

Question

hi, i have something want to ask about my coding, this is my coding
void StudentIN::display(){
cout << "Please enter your name: ";
getline(cin,name);

cout << "ID: ";
getline(cin,noID);

cout << " Which one you want to reserved? " << endl;
cout << " 1 : Room and Lecturing Equipment" << endl;
cout << " 2 : Room only" << endl;
cout << " 3 : Lecturing Equipment" << endl;

cout <<"Choice: ";
getline(cin,roomReserved);

cout <<"Please Enter Date(dd/mm/yy): ";
getline(cin,date);

cout <<"Please Enter Time( Start Time ):";
getline(cin,sTime);

cout <<"Please Enter Time( End Time ):";
getline(cin,eTime);

cout << "Your submission is SUCCESS. Please wait for our response" << endl;
}

how do we check the user key-in date/choice is valid or not?? sorry im beginner, thank you in advance
(this program form .h file) and from class StudentIN.