extern uint64_t utime_since(const struct timespec *, const struct timespec *);
extern uint64_t utime_since_now(const struct timespec *);
extern uint64_t mtime_since(const struct timespec *, const struct timespec *);
extern uint64_t utime_since(const struct timespec *, const struct timespec *);
extern uint64_t utime_since_now(const struct timespec *);
extern uint64_t mtime_since(const struct timespec *, const struct timespec *);