5#include <sys/timespec.h>
char * asctime_r(const struct tm *tm, char *buf)
struct tm * localtime(const time_t *timep)
struct tm * gmtime(const time_t *timep)
char * ctime_r(const time_t *timep, char *buf)
struct tm * gmtime_r(const time_t *timep, struct tm *result)
struct tm * localtime_r(const time_t *timep, struct tm *result)
char * ctime(const time_t *timep)
char * asctime(const struct tm *tm)
time_t mktime(struct tm *tm)