How to display a system date and time using c++

#include <ctime>

#include <iostream>

using namespace std;

int main() {

    time_t t = time(0);   // get time now

    struct tm * now = localtime( & t );

    cout <<  now->tm_mday << '-'//day

         << (now->tm_mon +1 )  << '-'//month

         << (now->tm_year +1900 )//year

         <<endl

         <<now->tm_hour//hour

         <<'-'<<now->tm_min//min

         <<'-'<< now->tm_sec//sec

         << endl;

         return 0;

}