double round(double x);

typedef long int suseconds_t;

struct timeval {
	time_t tv_sec;			/* seconds since 1970-01-01 */
	suseconds_t tv_usec;	/* microseconds */
};

struct timezone {
	int tz_minuteswest;
	int tz_dsttime;
};

int gettimeofday(struct timeval *tp, struct timezone *tzp);

struct tm * gmtime_r(time_t const *t, struct tm *tp);