MAX_TIME
if (num > MAX_TIME / 10)
if (num > MAX_TIME - (*P - '0'))
#define MAX_DAY (MAX_TIME / DAY)
#define MAX_HOUR (MAX_TIME / HOUR)
#define MAX_MIN (MAX_TIME / 60)
#define SUM_OK(a, b) (((a) > 0) ? ( (b) <= MAX_TIME - (a)) : (MIN_TIME - (a) <= (b)))