43 if (dst > 0) lt += dst;
int16_t tm_isdst
Daylight Saving Time flag [-1/0/1].
int(* __dst_ptr)(const time_t *, int32_t *)
struct tm * gmtime_r(const time_t *timer, struct tm *timeptr)
struct tm * localtime_r(const time_t *timer, struct tm *timeptr)