Duong2amlich.php

<?php

// https://nosomovo.xyz/2017/09/06/code-php-chuyen-doi-am-duong-lich/
// //1. Chuyển từ dương lịch sang âm lịch
// $dl_ngay=13;
// $dl_thang=11;
// $dl_nam=2019;
// $timezone='7.0';
// $ngayamlich=$dateconverter->convertSolar2Lunar($dl_ngay, $dl_thang, $dl_nam, $timezone);
// var_dump($ngayamlich); //để xem kết quả

// //2. Chuyển từ âm lịch sang dương lịch
// $al_ngay=17;
// $al_thang=10;
// $al_nam=2019;
// $lathangnhuan=0; //nếu là tháng nhuận thì set giá trị là 1
// $timezone='7.0';

// $ngayduonglich=$dateconverter->convertLunar2Solar($al_ngay, $al_thang, $al_nam, $lathangnhuan,$timezone);
// echo "<br>";
// var_dump($ngayduonglich); //để xem kết quả

class Duong2amlich
{
	public function INT( $d )
	{
		return floor( $d ) ;
	}

	public function jdFromDate( $dd, $mm, $yy )
	{
		$a = $this::INT( ( 14 - $mm ) / 12 ) ;
		$y = $yy + 4800 - $a ;
		$m = $mm + 12 * $a - 3 ;
		$jd = $dd + $this::INT( ( 153 * $m + 2 ) / 5 ) + 365 * $y + $this::INT( $y / 4 ) - $this::INT( $y /
						100 ) + $this::INT( $y / 400 ) - 32045 ;
		if ( $jd < 2299161 )
		{
						$jd = $dd + $this::INT( ( 153 * $m + 2 ) / 5 ) + 365 * $y + $this::INT( $y / 4 ) -
										32083 ;
		}
		return $jd ;
	}

	public function jdToDate( $jd )
	{
		if ( $jd > 2299160 )
		{ // After 5/10/1582, Gregorian calendar
						$a = $jd + 32044 ;
						$b = $this::INT( ( 4 * $a + 3 ) / 146097 ) ;
						$c = $a - $this::INT( ( $b * 146097 ) / 4 ) ;
		}
		else
		{
						$b = 0 ;
						$c = $jd + 32082 ;
		}
		$d = $this::INT( ( 4 * $c + 3 ) / 1461 ) ;
		$e = $c - $this::INT( ( 1461 * $d ) / 4 ) ;
		$m = $this::INT( ( 5 * $e + 2 ) / 153 ) ;
		$day = $e - $this::INT( ( 153 * $m + 2 ) / 5 ) + 1 ;
		$month = $m + 3 - 12 * $this::INT( $m / 10 ) ;
		$year = $b * 100 + $d - 4800 + $this::INT( $m / 10 ) ;
		//echo "day = $day, month = $month, year = $year\n";
		return array(
						$day,
						$month,
						$year
					);
	}

	public function getNewMoonDay( $k, $timeZone )
	{
		$T = $k / 1236.85; // Time in Julian centuries from 1900 January 0.5
		$T2 = $T * $T;
		$T3 = $T2 * $T;
		$dr = M_PI / 180;
		$Jd1 = 2415020.75933 + 29.53058868 * $k + 0.0001178 * $T2 - 0.000000155 * $T3;
		$Jd1 = $Jd1 + 0.00033 * sin( ( 166.56 + 132.87 * $T - 0.009173 * $T2 ) * $dr); // Mean new moon
		$M = 359.2242 + 29.10535608 * $k - 0.0000333 * $T2 - 0.00000347 * $T3; // Sun's mean anomaly
		$Mpr = 306.0253 + 385.81691806 * $k + 0.0107306 * $T2 + 0.00001236 * $T3; // Moon's mean anomaly
		$F = 21.2964 + 390.67050646 * $k - 0.0016528 * $T2 - 0.00000239 * $T3; // Moon's argument of latitude
		$C1 = ( 0.1734 - 0.000393 * $T ) * sin( $M * $dr ) + 0.0021 * sin( 2 * $dr * $M );
		$C1 = $C1 - 0.4068 * sin( $Mpr * $dr ) + 0.0161 * sin( $dr * 2 * $Mpr);
		$C1 = $C1 - 0.0004 * sin( $dr * 3 * $Mpr);
		$C1 = $C1 + 0.0104 * sin( $dr * 2 * $F ) - 0.0051 * sin( $dr * ( $M + $Mpr));
		$C1 = $C1 - 0.0074 * sin( $dr * ( $M - $Mpr ) ) + 0.0004 * sin( $dr * ( 2 * $F + $M ));
		$C1 = $C1 - 0.0004 * sin( $dr * ( 2 * $F - $M ) ) - 0.0006 * sin( $dr * ( 2 * $F + $Mpr ));
		$C1 = $C1 + 0.0010 * sin( $dr * ( 2 * $F - $Mpr ) ) + 0.0005 * sin( $dr * ( 2 * $Mpr + $M ));
		if ( $T < -11 )
		{
						$deltat = 0.001 + 0.000839 * $T + 0.0002261 * $T2 - 0.00000845 * $T3 - 0.000000081 * $T * $T3 ;
		}
		else
		{
						$deltat = -0.000278 + 0.000265 * $T + 0.000262 * $T2;
		}
		
		$JdNew = $Jd1 + $C1 - $deltat;
		//echo "JdNew = $JdNew\n";
		return $this::INT( $JdNew + 0.5 + $timeZone / 24 );
	}

	public function getSunLongitude( $jdn, $timeZone )
	{
		$T = ( $jdn - 2451545.5 - $timeZone / 24 ) / 36525; // Time in Julian centuries from 2000-01-01 12:00:00 GMT
		$T2 = $T * $T;
		$dr = M_PI / 180; // degree to radian
		$M = 357.52910 + 35999.05030 * $T - 0.0001559 * $T2 - 0.00000048 * $T * $T2; // mean anomaly, degree
		$L0 = 280.46645 + 36000.76983 * $T + 0.0003032 * $T2; // mean longitude, degree
		$DL = ( 1.914600 - 0.004817 * $T - 0.000014 * $T2 ) * sin( $dr * $M );
		$DL = $DL + ( 0.019993 - 0.000101 * $T ) * sin( $dr * 2 * $M ) + 0.000290 * sin( $dr * 3 * $M );
		$L = $L0 + $DL; // true longitude, degree
		//echo "\ndr = $dr, M = $M, T = $T, DL = $DL, L = $L, L0 = $L0\n";
		// obtain apparent longitude by correcting for nutation and aberration
		$omega = 125.04 - 1934.136 * $T;
		$L = $L - 0.00569 - 0.00478 * sin( $omega * $dr );
		$L = $L * $dr;
		$L = $L - M_PI * 2 * ( $this::INT( $L / ( M_PI * 2 ) ) ); // Normalize to (0, 2*PI)
		return $this::INT( $L / M_PI * 6 );
	}

	public function getLunarMonth11( $yy, $timeZone )
	{
		$off = $this->jdFromDate( 31, 12, $yy ) - 2415021;
		$k = $this::INT( $off / 29.530588853 );
		$nm = $this::getNewMoonDay( $k, $timeZone );
		$sunLong = $this::getSunLongitude( $nm, $timeZone ); // sun longitude at local midnight
		if ( $sunLong >= 9 )
		{
						$nm = $this::getNewMoonDay( $k - 1, $timeZone );
		}
		return $nm;
	}

	public function getLeapMonthOffset( $a11, $timeZone )
	{
		$k = $this::INT( ( $a11 - 2415021.076998695 ) / 29.530588853 + 0.5 );
		$last = 0;
		$i = 1; // We start with the month following lunar month 11
		$arc = $this::getSunLongitude( $this::getNewMoonDay( $k + $i, $timeZone ), $timeZone );
		do
		{
			$last = $arc;
			$i = $i + 1;
			$arc = $this::getSunLongitude( $this::getNewMoonDay( $k + $i, $timeZone ), $timeZone );
		} 
		while ( $arc != $last && $i < 14 );
		return $i - 1 ;
	}

	/* Comvert solar date dd/mm/yyyy to the corresponding lunar date */
	public function convertSolar2Lunar( $dd, $mm, $yy, $timeZone )
	{
		$dayNumber = $this::jdFromDate( $dd, $mm, $yy );
		$k = $this::INT( ( $dayNumber - 2415021.076998695 ) / 29.530588853 );
		$monthStart = $this::getNewMoonDay( $k + 1, $timeZone );
		if ($monthStart > $dayNumber)
		{
			$monthStart = $this::getNewMoonDay( $k, $timeZone );
		}
		$a11 = $this::getLunarMonth11( $yy, $timeZone ) ;
		$b11 = $a11 ;
		if ( $a11 >= $monthStart )
		{
			$lunarYear = $yy;
			$a11 = $this::getLunarMonth11( $yy - 1, $timeZone );
		}
		else
		{
			$lunarYear = $yy + 1;
			$b11 = $this::getLunarMonth11( $yy + 1, $timeZone );
		}
		$lunarDay = $dayNumber - $monthStart + 1 ;
		$diff = $this::INT( ( $monthStart - $a11 ) / 29 ) ;
		$lunarLeap = 0 ;
		$lunarMonth = $diff + 11 ;
		if ( $b11 - $a11 > 365 )
		{
			$leapMonthDiff = $this::getLeapMonthOffset( $a11, $timeZone ) ;
			if ( $diff >= $leapMonthDiff )
			{
							$lunarMonth = $diff + 10 ;
							if ( $diff == $leapMonthDiff )
							{
											$lunarLeap = 1 ;
							}
			}
		}
		if ( $lunarMonth > 12 )
		{
			$lunarMonth = $lunarMonth - 12 ;
		}
		if ( $lunarMonth >= 11 && $diff < 4 )
		{
			$lunarYear -= 1 ;
		}
		return array(
						$lunarDay,
						$lunarMonth,
						$lunarYear,
						$lunarLeap ) ;
	}

	/* Convert a lunar date to the corresponding solar date */
	public function convertLunar2Solar( $lunarDay, $lunarMonth, $lunarYear, $lunarLeap,
					$timeZone )
	{
		if ( $lunarMonth < 11 )
		{
						$a11 = $this::getLunarMonth11( $lunarYear - 1, $timeZone ) ;
						$b11 = $this::getLunarMonth11( $lunarYear, $timeZone ) ;
		}
		else
		{
						$a11 = $this::getLunarMonth11( $lunarYear, $timeZone ) ;
						$b11 = $this::getLunarMonth11( $lunarYear + 1, $timeZone ) ;
		}
		$k = $this::INT( 0.5 + ( $a11 - 2415021.076998695 ) / 29.530588853 ) ;
		$off = $lunarMonth - 11 ;
		if ( $off < 0 )
		{
						$off += 12 ;
		}
		if ( $b11 - $a11 > 365 )
		{
						$leapOff = $this::getLeapMonthOffset( $a11, $timeZone ) ;
						$leapMonth = $leapOff - 2 ;
						if ( $leapMonth < 0 )
						{
										$leapMonth += 12 ;
						}
						if ( $lunarLeap != 0 && $lunarMonth != $leapMonth )
						{
										return array(
														0,
														0,
														0 ) ;
						}
						else
										if ( $lunarLeap != 0 || $off >= $leapOff )
										{
														$off += 1 ;
										}
		}
		$monthStart = $this::getNewMoonDay( $k + $off, $timeZone ) ;
		return $this::jdToDate( $monthStart + $lunarDay - 1 ) ;
	}
}

?>