#include <iostream>
#include <sstream>
#include <ctime>
#include <iomanip>
int main() {
std::istringstream ss("11:41:17");
struct std::tm tm;
ss >> std::get_time(&tm, "%H:%M:%S");
std::cout << std::put_time(&tm, "%H:%M:%S") << '\n';
std::time_t timet = mktime(&tm);
std::cout << asctime(gmtime(&timet));
}
/*
run:
11:41:17
Mon Sep 23 11:41:17 -7201818
*/