dalla timelib.h
typedef struct {
uint8_t Second;
uint8_t Minute;
uint8_t Hour;
uint8_t Wday; // day of week, sunday is day 1
uint8_t Day;
uint8_t Month;
uint8_t Year; // offset from 1970;
} tmElements_t, TimeElements, *tmElementsPtr_t;
//convenience macros to convert to and from tm years
#define tmYearToCalendar(Y) ((Y) + 1970) // full four digit year
#define CalendarYrToTm(Y) ((Y) - 1970)
#define tmYearToY2k(Y) ((Y) - 30) // offset is from 2000
#define y2kYearToTm(Y) ((Y) + 30)