演示效果:

Array
(
    [0] => 2020
    [1] => 四月
    [2] => 十三
    [3] => 庚子
    [4] => 4
    [5] => 13
    [6] => 鼠
    [7] => 4
)

  新建一个index.php文件

<?php 
header("Content-Type:text/html;charset=utf-8");
include "lunar.php";
$Lunar = new Lunar();
 
$year = date('Y');
$month = date('m');
$day = date('d');
$month = $Lunar->convertSolarToLunar($year,$month,$day);
 
echo '<pre>';
print_r($month);

  按照上面的示例,把index.php和lunar.php者两个文件放同一目录下就可以直接调用了

  lunar.php类文件

class Lunar{
    var $MIN_YEAR=1891;
    var $MAX_YEAR=2100;
    var $lunarInfo=array(
        array(0,2,9,21936),array(6,1,30,9656),array(0,2,17,9584),array(0,2,6,21168),
        array(5,1,26,43344),array(0,2,13,59728),array(0,2,2,27296),array(3,1,22,44368),
        array(0,2,10,43856),array(8,1,30,19304),array(0,2,19,19168),array(0,2,8,42352),
        array(5,1,29,21096),array(0,2,16,53856),array(0,2,4,55632),array(4,1,25,27304),
        array(0,2,13,22176),array(0,2,2,39632),array(2,1,22,19176),array(0,2,10,19168),
        array(6,1,30,42200),array(0,2,18,42192),array(0,2,6,53840),array(5,1,26,54568),
        array(0,2,14,46400),array(0,2,3,54944),array(2,1,23,38608),array(0,2,11,38320),
        array(7,2,1,18872),array(0,2,20,18800),array(0,2,8,42160),array(5,1,28,45656),
        array(0,2,16,27216),array(0,2,5,27968),array(4,1,24,44456),array(0,2,13,11104),
        array(0,2,2,38256),array(2,1,23,18808),array(0,2,10,18800),array(6,1,30,25776),
        array(0,2,17,54432),array(0,2,6,59984),array(5,1,26,27976),array(0,2,14,23248),
        array(0,2,4,11104),array(3,1,24,37744),array(0,2,11,37600),array(7,1,31,51560),
        array(0,2,19,51536),array(0,2,8,54432),array(6,1,27,55888),array(0,2,15,46416),
        array(0,2,5,22176),array(4,1,25,43736),array(0,2,13,9680),array(0,2,2,37584),
        array(2,1,22,51544),array(0,2,10,43344),array(7,1,29,46248),array(0,2,17,27808),
        array(0,2,6,46416),array(5,1,27,21928),array(0,2,14,19872),array(0,2,3,42416),
        array(3,1,24,21176),array(0,2,12,21168),array(8,1,31,43344),array(0,2,18,59728),
        array(0,2,8,27296),array(6,1,28,44368),array(0,2,15,43856),array(0,2,5,19296),
        array(4,1,25,42352),array(0,2,13,42352),array(0,2,2,21088),array(3,1,21,59696),
        array(0,2,9,55632),array(7,1,30,23208),array(0,2,17,22176),array(0,2,6,38608),
        array(5,1,27,19176),array(0,2,15,19152),array(0,2,3,42192),array(4,1,23,53864),
        array(0,2,11,53840),array(8,1,31,54568),array(0,2,18,46400),array(0,2,7,46752),
        array(6,1,28,38608),array(0,2,16,38320),array(0,2,5,18864),array(4,1,25,42168),
        array(0,2,13,42160),array(10,2,2,45656),array(0,2,20,27216),array(0,2,9,27968),
        array(6,1,29,44448),array(0,2,17,43872),array(0,2,6,38256),array(5,1,27,18808),
        array(0,2,15,18800),array(0,2,4,25776),array(3,1,23,27216),array(0,2,10,59984),
        array(8,1,31,27432),array(0,2,19,23232),array(0,2,7,43872),array(5,1,28,37736),
        array(0,2,16,37600),array(0,2,5,51552),array(4,1,24,54440),array(0,2,12,54432),
        array(0,2,1,55888),array(2,1,22,23208),array(0,2,9,22176),array(7,1,29,43736),
        array(0,2,18,9680),array(0,2,7,37584),array(5,1,26,51544),array(0,2,14,43344),
        array(0,2,3,46240),array(4,1,23,46416),array(0,2,10,44368),array(9,1,31,21928),
        array(0,2,19,19360),array(0,2,8,42416),array(6,1,28,21176),array(0,2,16,21168),
        array(0,2,5,43312),array(4,1,25,29864),array(0,2,12,27296),array(0,2,1,44368),
        array(2,1,22,19880),array(0,2,10,19296),array(6,1,29,42352),array(0,2,17,42208),
        array(0,2,6,53856),array(5,1,26,59696),array(0,2,13,54576),array(0,2,3,23200),
        array(3,1,23,27472),array(0,2,11,38608),array(11,1,31,19176),array(0,2,19,19152),
        array(0,2,8,42192),array(6,1,28,53848),array(0,2,15,53840),array(0,2,4,54560),
        array(5,1,24,55968),array(0,2,12,46496),array(0,2,1,22224),array(2,1,22,19160),
        array(0,2,10,18864),array(7,1,30,42168),array(0,2,17,42160),array(0,2,6,43600),
        array(5,1,26,46376),array(0,2,14,27936),array(0,2,2,44448),array(3,1,23,21936),
        array(0,2,11,37744),array(8,2,1,18808),array(0,2,19,18800),array(0,2,8,25776),
        array(6,1,28,27216),array(0,2,15,59984),array(0,2,4,27424),array(4,1,24,43872),
        array(0,2,12,43744),array(0,2,2,37600),array(3,1,21,51568),array(0,2,9,51552),
        array(7,1,29,54440),array(0,2,17,54432),array(0,2,5,55888),array(5,1,26,23208),
        array(0,2,14,22176),array(0,2,3,42704),array(4,1,23,21224),array(0,2,11,21200),
        array(8,1,31,43352),array(0,2,19,43344),array(0,2,7,46240),array(6,1,27,46416),
        array(0,2,15,44368),array(0,2,5,21920),array(4,1,24,42448),array(0,2,12,42416),
        array(0,2,2,21168),array(3,1,22,43320),array(0,2,9,26928),array(7,1,29,29336),
        array(0,2,17,27296),array(0,2,6,44368),array(5,1,26,19880),array(0,2,14,19296),
        array(0,2,3,42352),array(4,1,24,21104),array(0,2,10,53856),array(8,1,30,59696),
        array(0,2,18,54560),array(0,2,7,55968),array(6,1,27,27472),array(0,2,15,22224),
        array(0,2,5,19168),array(4,1,25,42216),array(0,2,12,42192),array(0,2,1,53584),
        array(2,1,21,55592),array(0,2,9,54560)
    );
 
 
    /** 
    * 将阳历转换为阴历 
    * @param year 公历-年 
    * @param month 公历-月 
    * @param date 公历-日 
    */ 
    function convertSolarToLunar($year='',$month='',$date=''){
        $yearData=$this->lunarInfo[$year-$this->MIN_YEAR];
        if($year==$this->MIN_YEAR&&$month<=2&&$date<=9){ 
            return array(1891,'正月','初一','辛卯',1,1,'兔');
        }
        return $this->getLunarByBetween($year,$this->getDaysBetweenSolar($year,$month,$date,$yearData[1],$yearData[2]));
    }
 
    function convertSolarMonthToLunar($year,$month){
        $yearData=$this->lunarInfo[$year-$this->MIN_YEAR];
        if($year==$this->MIN_YEAR&&$month<=2&&$date<=9){ 
            return array(1891,'正月','初一','辛卯',1,1,'兔');
        }
        $month_days_ary=array(31,28,31,30,31,30,31,31,30,31,30,31);
        $dd=$month_days_ary[$month];
        if($this->isLeapYear($year)&& $month==2)$dd++;
        $lunar_ary=array();
        for ($i=1;$i<$dd;$i++){
            $array=$this->getLunarByBetween($year,$this->getDaysBetweenSolar($year,$month,$i,$yearData[1],$yearData[2]));
            $array[]=$year.'-'.$month.'-'.$i;
            $lunar_ary[$i]=$array;
        }
        return $lunar_ary;
    }
    /** 
    * 将阴历转换为阳历 
    * @param year 阴历-年 
    * @param month 阴历-月,闰月处理:例如如果当年闰五月,那么第二个五月就传六月,相当于阴历有13个月,只是有的时候第13个月的天数为0 
    * @param date 阴历-日 
    */ 
    function convertLunarToSolar($year,$month,$date){ 
        $yearData=$this->lunarInfo[$year-$this->MIN_YEAR];
        $between=$this->getDaysBetweenLunar($year,$month,$date);
        $res=mktime(0,0,0,$yearData[1],$yearData[2],$year);
        $res=date('Y-m-d',$res+$between*24*60*60);
        $day=explode('-',$res);
        $year=$day[0];
        $month=$day[1];
        $day=$day[2];
        return array($year,$month,$day);
    }
    /** 
    * 判断是否是闰年 
    * @param year 
    */ 
    function isLeapYear($year){ 
        return (($year%4==0&&$year%100!=0)||($year%400==0));
    }
    /** 
    * 获取干支纪年 
    * @param year 
    */ 
    function getLunarYearName($year){ 
        $sky=array('庚','辛','壬','癸','甲','乙','丙','丁','戊','己');
        $earth=array('申','酉','戌','亥','子','丑','寅','卯','辰','巳','午','未');
        $year=$year.'';
        return $sky[$year{3}].$earth[$year%12];
    }
    /** 
    * 根据阴历年获取生肖 
    * @param year 阴历年 
    */ 
    function getYearZodiac($year){ 
        $zodiac=array('猴','鸡','狗','猪','鼠','牛','虎','兔','龙','蛇','马','羊');
        return $zodiac[$year%12];
    }
    /** 
    * 获取阳历月份的天数 
    * @param year 阳历-年 
    * @param month 阳历-月 
    */ 
    function getSolarMonthDays($year,$month){ 
        $monthHash=array('1'=>31,'2'=>$this->isLeapYear($year)?29:28,'3'=>31,'4'=>30,'5'=>31,'6'=>30,'7'=>31,'8'=>31,'9'=>30,'10'=>31,'11'=>30,'12'=>31);
        return $monthHash["$month"];
    }
    /** 
    * 获取阴历月份的天数 
    * @param year 阴历-年 
    * @param month 阴历-月,从一月开始 
    */ 
    function getLunarMonthDays($year,$month){ 
        $monthData=$this->getLunarMonths($year);
        return $monthData[$month-1];
    }
    /** 
    * 获取阴历每月的天数的数组 
    * @param year 
    */ 
    function getLunarMonths($year){ 
        $yearData=$this->lunarInfo[$year-$this->MIN_YEAR];
        $leapMonth=$yearData[0];
        $bit=decbin($yearData[3]);
        for ($i=0;$i<strlen($bit);$i ++){
            $bitArray[$i]=substr($bit,$i,1);
        }
        for($k=0,$klen=16-count($bitArray);$k<$klen;$k++){ 
            array_unshift($bitArray,'0');
        }
        $bitArray=array_slice($bitArray,0,($leapMonth==0?12:13));
        for($i=0;$i<count($bitArray);$i++){ 
            $bitArray[$i]=$bitArray[$i] + 29;
        }
        return $bitArray;
    }
    /** 
    * 获取农历每年的天数 
    * @param year 农历年份 
    */ 
    function getLunarYearDays($year){ 
        $yearData=$this->lunarInfo[$year-$this->MIN_YEAR];
        $monthArray=$this->getLunarYearMonths($year);
        $len=count($monthArray);
        return ($monthArray[$len-1]==0?$monthArray[$len-2]:$monthArray[$len-1]);
    }
    function getLunarYearMonths($year){//debugger;
        $monthData=$this->getLunarMonths($year);
        $res=array();
        $temp=0;
        $yearData=$this->lunarInfo[$year-$this->MIN_YEAR];
        $len=($yearData[0]==0?12:13);
        for($i=0;$i<$len;$i++){ 
            $temp=0;
            for($j=0;$j<=$i;$j++){ 
                $temp+=$monthData[$j];
            }
            array_push($res,$temp);
        }
        return $res;
    }
    /** 
    * 获取闰月 
    * @param year 阴历年份 
    */ 
    function getLeapMonth($year){ 
        $yearData=$this->lunarInfo[$year-$this->MIN_YEAR];
        return $yearData[0];
    }
    /** 
    * 计算阴历日期与正月初一相隔的天数 
    * @param year http://www.codetc.com/
    * @param month 
    * @param date 
    */ 
    function getDaysBetweenLunar($year,$month,$date){ 
        $yearMonth=$this->getLunarMonths($year);
        $res=0;
        for($i=1;$i<$month;$i++){ 
            $res+=$yearMonth[$i-1];
        }
        $res+=$date-1;
        return $res;
    }
    /** 
    * 计算2个阳历日期之间的天数 
    * @param year 阳历年 
    * @param cmonth 
    * @param cdate 
    * @param dmonth 阴历正月对应的阳历月份 
    * @param ddate 阴历初一对应的阳历天数 
    */ 
    function getDaysBetweenSolar($year,$cmonth,$cdate,$dmonth,$ddate){ 
        $a=mktime(0,0,0,$cmonth,$cdate,$year);
        $b=mktime(0,0,0,$dmonth,$ddate,$year);
        return ceil(($a-$b)/24/3600);
    }
    /** 
    * 根据距离正月初一的天数计算阴历日期 
    * @param year 阳历年 
    * @param between 天数 
    */ 
    function getLunarByBetween($year,$between){//debugger;
        $lunarArray=array();
        $yearMonth=array();
        $t=0;
        $e=0;
        $leapMonth=0;
        $m='';
        if($between==0){ 
            array_push($lunarArray,$year,'正月','初一');
            $t=1;
            $e=1;
        }else{ 
            $year=$between>0? $year : ($year-1);
            $yearMonth=$this->getLunarYearMonths($year);
            $leapMonth=$this->getLeapMonth($year);
            $between=$between>0?$between : ($this->getLunarYearDays($year)+$between);
            for($i=0;$i<13;$i++){ 
                if($between==$yearMonth[$i]){ 
                    $t=$i+2;
                    $e=1;
                    break;
                }else if($between<$yearMonth[$i]){ 
                    $t=$i+1;
                    $e=$between-(empty($yearMonth[$i-1])?0:$yearMonth[$i-1])+1;
                    break;
                }
            }
            $m=($leapMonth!=0&&$t==$leapMonth+1)?('闰'.$this->getCapitalNum($t- 1,true)):$this->getCapitalNum(($leapMonth!=0&&$leapMonth+1<$t?($t-1):$t),true);
            array_push($lunarArray,$year,$m,$this->getCapitalNum($e,false));
        }
        array_push($lunarArray,$this->getLunarYearName($year));// 天干地支 
        array_push($lunarArray,$t,$e);
        array_push($lunarArray,$this->getYearZodiac($year));// 12生肖 
        array_push($lunarArray,$leapMonth);// 闰几月 
        return $lunarArray;
    }
    /** 
    * 获取数字的阴历叫法 
    * @param num 数字 
    * @param isMonth 是否是月份的数字 
    */ 
    function getCapitalNum($num,$isMonth){ 
        $isMonth=$isMonth||false;
        $dateHash=array('0'=>'','1'=>'一','2'=>'二','3'=>'三','4'=>'四','5'=>'五','6'=>'六','7'=>'七','8'=>'八','9'=>'九','10'=>'十 ');
        $monthHash=array('0'=>'','1'=>'正月','2'=>'二月','3'=>'三月','4'=>'四月','5'=>'五月','6'=>'六月','7'=>'七月','8'=>'八月','9'=>'九月','10'=>'十月','11'=>'冬月','12'=>'腊月');
        $res='';
        if($isMonth){ 
            $res=$monthHash[$num];
        }else{ 
            if($num<=10){ 
                $res='初'.$dateHash[$num];
            }else if($num>10&&$num<20){ 
                $res='十'.$dateHash[$num-10];
            }else if($num==20){ 
                $res="二十";
            }else if($num>20&&$num<30){ 
                $res="廿".$dateHash[$num-20];
            }else if($num==30){ 
                $res="三十";
            }
        }
        return $res;
    }
}