_DaysInMonth
static int32 _DaysInMonth(int32 year, int32 month);
if (day < 1 || day > _DaysInMonth(year, month))
fDay = min_c(fDay, _DaysInMonth(fYear, fMonth));
fDay = min_c(fDay, _DaysInMonth(fYear, fMonth));
return _DaysInMonth(fYear, fMonth);