ostream& operator<<(ostream& os, const WorldClock& c) { WorldClock temp = c; temp.Tick(temp.time_difference()*secondOfTime); os << temp.hour() << ":" << temp.minute() << ":" << temp.second(); if (temp.time_difference() >= 0) os << " (+" << temp.time_difference() << ")"; else os << " (" << temp.time_difference() << ")"; return os; }