PHP 根据出生日期计算年龄、生肖、星座

/**
* 根据出生日期计算年龄、生肖、星座
* @param string $mydate = "2018-10-23" 日期
* @param string $symbol 符号
* @return $array  
* */
function birthday($mydate,$symbol='-'){
	
	//计算年龄
	$birth=$mydate;  
	list($by,$bm,$bd)=explode($symbol,$birth);       
	$cm=date('n');  
	$cd=date('j');       
	$age=date('Y')-$by-1;  
	if ($cm>$bm || $cm==$bm && $cd>$bd) $age++;   
	$array['age'] = $age;
	
	//计算生肖
	$animals = array(               
		'鼠', '牛', '虎', '兔', '龙', '蛇',
		'马', '羊', '猴', '鸡', '狗', '猪'      
	);
	$key = ($by - 1900) % 12; 
	$array['animals'] = $animals[$key];
	
	//计算星座
	$constellation_name = array( 
		'水瓶座','双鱼座','白羊座','金牛座','双子座','巨蟹座',
		'狮子座','处女座','天秤座','天蝎座)','射手座','摩羯座'
	);
	if ($bd <= 22){
		if ('1' !== $bm) $constellation = $constellation_name[$bm-2]; else $constellation = $constellation_name[11];
	}else $constellation = $constellation_name[$bm-1];
	$array['constellation'] = $constellation;
	
	return $array;
}