FIRST_SECOND
second = (secres == 0) ? 0 : tm->tm_sec -FIRST_SECOND;
otzsecond = (secres == 0) ? 0 : otztm.tm_sec -FIRST_SECOND;
#define SECOND_COUNT (LAST_SECOND - FIRST_SECOND + 1)
bit_nset(e->second, 0, (LAST_SECOND-FIRST_SECOND+1));