We currently have
void EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char **tzn, int style, char *str)
but tzn isn't used anywhere, only *tzn is used everywhere. Wouldn't it
be clearer to remove that one level of indirection and instead have the
signature be
void EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char *tzn, int style, char *str)
or better yet
void EncodeDateTime(struct pg_tm * tm, fsec_t fsec, const int *tzp, const char *tzn, int style, char *str)
