// airtime.h
// class models time data type
// overloads operators

#include <iostream.h>

class airtime
{	public:
		airtime (int h = 0, int m = 0) : hours(h), minutes(m) { }
        	airtime operator + (const airtime& right) const;
		int operator < (const airtime& right) const;
		airtime& operator += (const airtime& right);
		airtime& operator ++ ();
		airtime operator ++ (int);
		airtime operator - () const;
		airtime operator - (const airtime& right) const;
		friend istream& operator >> (istream& s, airtime& t);
		friend ostream& operator << (ostream& s, const airtime& t);
	private:
      		int hours;
      		int minutes;
};