find_days_month
.find_days_month = julian_find_days_month,
.find_days_month = NULL,
.find_days_month = find_days_month,
int (*find_days_month)(int month, struct cal_day **dayp,
int find_days_month(int month, struct cal_day **dayp, char **edp);
Calendar->find_days_month != NULL) {
return (Calendar->find_days_month)(di.month, dayp, edp);