IsLeapYear
bool IsLeapYear() const;
static bool IsLeapYear(int32 year);
if (date.Month() == 2 && date.Day() == 29 && !date.IsLeapYear(year))
if (month == 2 && IsLeapYear(year))
return IsLeapYear(fYear);
return IsLeapYear(fYear) ? 366 : 365;