从NSDate的日期获得星座，星座分个参照 http://www.chinaz.com/program/2009/1226/102350.shtml

starSign.m

- (NSString *)starSign:(NSDate *)date{

    if(!date)
        return @"处女座";
    
    NSString *info = @"水瓶座*0120*0219#双鱼座*0220*0320#白羊座*0321*0420#金牛座*0421*0521#双子座*0522*0621#巨蟹座*0622*0722#狮子座*0723*0823#处女座*0824*0923#天秤座*0924*1023#天蝎座*1024*1122#射手座*1123*1222#摩蝎座*1222*0119#";
    NSArray *array = [info componentsSeparatedByString:@"#"];
    
    NSString *starSignString = @"摩羯座";
    NSCalendar *calender = [NSCalendar currentCalendar];
    NSDateComponents *components = [calender components:(NSMonthCalendarUnit |  NSDayCalendarUnit) fromDate:date];
    
    for(NSString *infoString in array){
        if(!infoString||infoString.length<=1)
            continue;
        NSArray *detaiArray = [infoString componentsSeparatedByString:@"*"];
        NSString *from = [detaiArray objectAtIndex:1];
        int fromMonth = [[from substringFromIndex:0 length:2] intValue];
        int fromDay = [[from substringFromIndex:2 length:2] intValue];
        
        NSString *to = [detaiArray objectAtIndex:2];
        int toMonth = [[to substringFromIndex:0 length:2] intValue];
        int toDay = [[to substringFromIndex:2 length:2] intValue];
        
        NSString *starSine = [detaiArray objectAtIndex:0];
        
        if(components.month>=fromMonth&&components.month<=toMonth){
            if(components.month==fromMonth){
                if(components.day>=fromDay)
                    starSignString = starSine;
                return starSignString;
            }
            
            if(components.month==toMonth){
                if(components.day<=toDay)
                    starSignString = starSine;
                return starSignString;
            }
        }
    }
    
    return starSignString;
}