根据生日计算星座

 +(NSString *)calculateConstellationWithMonth:(NSInteger)month day:(NSInteger)day
  {
  NSString *astroString = @"魔羯水瓶双鱼白羊金牛双子巨蟹狮子处女天秤天蝎射手魔羯";
NSString *astroFormat = @"102123444543";

  NSString *result;

  if (month<1 || month>12 || day<1 || day>31){
    return @"错误日期格式!";
  }

if(month==2 && day>29)
{
    return @"错误日期格式!!";
}else if(month==4 || month==6 || month==9 || month==11) {
    if (day>30) {
        return @"错误日期格式!!!";
    }
}

result=[NSString stringWithFormat:@"%@",[astroString substringWithRange:NSMakeRange(month*2-(day < [[astroFormat substringWithRange:NSMakeRange((month-1), 1)] intValue] - (-19))*2,2)]];

return [NSString stringWithFormat:@"%@座",result];
}