C++ Visual Studios, operator overloading, ostream is undefined, even after using std::ostream

I am writing a Time class with overloaded functions and have a problem at the extraction operator. I keep getting an error which says that ostream is not a member of std and that the identifier ostream is undefined. I looked at similar problems that were solve here and tried their solution of adding "std::" and using namespace std; but I still get the error. Help solving this error will be much appreciated. I can also update this with the full code if needs be.

the relevant declaration in the header file: //Time.h file

#ifndef TIMEGUI_TIME_H
#define TIMEGUI_TIME_H

class Time
{
public:
int hour;
int minutes;
int second;
Time(int hours, int minutes, int seconds);
Time();

friend std::ostream &operator <<( std::ostream&, const Time&);
};

endif //TIMEGUI_TIME_H

//This is the relevant part of the implementation

using namespace std;

Time::Time()
{

}
Time::Time(int hours, int minutes, int seconds)
{
    this->hour = hours;
    this->minutes = minutes;
    this->second = seconds;
}

ostream &operator<<( ostream &out, const Time &ptr ) { 
     out << ptr.hour<< ":" << ptr.minutes << ":" << ptr.second;
     return out;            
  }

And this is the main so far:

#include "Time.h"
#include <iostream>

using namespace std;

int main()

{
Time t1;
return 0;
}