// The gmtime() function converts the calendar time timep to broken-down
// time representation, expressed in Coordinated Universal Time (UTC).
const struct tm* gmtime(time_t time){
static struct tm tm;
uint32_t dayclock = time % SECS_DAY;
tm.tm_mday = time / SECS_DAY;
tm.tm_year = EPOCH_YR;
tm.tm_sec = time % 60UL;
tm.tm_min = (time % 3600UL) / 60;
tm.tm_hour = dayclock / 3600UL;
tm.tm_wday = (tm.tm_mday + 4) % 7; /* day 0 was a thursday */
while (tm.tm_mday >= YEARSIZE(tm.tm_year)) {
tm.tm_mday -= YEARSIZE(tm.tm_year);
tm.tm_year++;
}
tm.tm_mon = 0;
while (tm.tm_mday >= monthlen(LEAPYEAR(tm.tm_year),tm.tm_mon)) {
tm.tm_mday -= monthlen(LEAPYEAR(tm.tm_year),tm.tm_mon);
tm.tm_mon++;
}
tm.tm_mday++;
return &tm;
}
// gmtime -- convert calendar time (sec since 1970) into broken down time
// returns something like Fri 2007-10-19 in day and 01:02:21 in clock
// The return values is the minutes as integer. This way you can update
// the entire display when the minutes have changed and otherwise just
// write current time (clock). That way an LCD display needs complete
// re-write only every minute.
uint8_t gmtime(const uint32_t time,char *day, char *clock)
{
char dstr[4];
uint8_t i;
uint32_t dayclock;
uint16_t dayno;
uint16_t tm_year = EPOCH_YR;
uint8_t tm_sec,tm_min,tm_hour,tm_wday,tm_mon;
dayclock = (time) % SECS_DAY;
dayno = (time) / SECS_DAY;
extern newMinute;
tm_sec = dayclock % 60UL;
newMinute=tm_sec;
tm_min = (dayclock % 3600UL) / 60;
tm_hour = dayclock / 3600UL;
tm_wday = (dayno + 4) % 7; /* day 0 was a Thursday */
while (dayno >= YEARSIZE(tm_year)) {
dayno -= YEARSIZE(tm_year);
tm_year++;
}
tm_mon = 0;
while (dayno >= monthlen(LEAPYEAR(tm_year),tm_mon)) {
dayno -= monthlen(LEAPYEAR(tm_year),tm_mon);
tm_mon++;
}
i=0;
while (i<3){
dstr[i]= pgm_read_byte(&(day_abbrev[tm_wday*3 + i]));
i++;
}
dstr[3]='\0';
sprintf_P(day,PSTR("%s %u-%02u-%02u"),dstr,tm_year,tm_mon+1,dayno + 1);
sprintf_P(clock,PSTR("%02u:%02u:%02u"),tm_hour,tm_min,tm_sec);
return(tm_min);
}
