typedef struct {
  unsigned year;
  unsigned is_leap;
  unsigned jday;
  unsigned month;
  unsigned mday;
  unsigned wday;
  unsigned hour;
  unsigned minute;
  unsigned second;
  unsigned nanosecond;
} UTC;

typedef struct {
  int64_t s;
  int64_t ns;
} EPOCH;

typedef struct {
  unsigned hour;
  unsigned minute;
  unsigned second;
  unsigned nanosecond;
} ST;