2299160) { // After 5/10/1582, Gregorian calendar
$a = $jd + 32044;
$b = INT((4*$a+3)/146097);
$c = $a - INT(($b*146097)/4);
} else {
$b = 0;
$c = $jd + 32082;
}
$d = INT((4*$c+3)/1461);
$e = $c - INT((1461*$d)/4);
$m = INT((5*$e+2)/153);
$day = $e - INT((153*$m+2)/5) + 1;
$month = $m + 3 - 12*INT($m/10);
$year = $b*100 + $d - 4800 + INT($m/10);
//echo "day = $day, month = $month, year = $year\n";
return array($day, $month, $year);
}
function getNewMoonDay($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 = $JdNew\n";
return INT($JdNew + 0.5 + $timeZone/24);
}
function getSunLongitude($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 = $L - 0.00569 - 0.00478 * Math.sin($omega * $dr);
$L = $L*$dr;
$L = $L - M_PI*2*(INT($L/(M_PI*2))); // Normalize to (0, 2*PI)
return INT($L/M_PI*6);
}
function getLunarMonth11($yy, $timeZone) {
$off = jdFromDate(31, 12, $yy) - 2415021;
$k = INT($off / 29.530588853);
$nm = getNewMoonDay($k, $timeZone);
$sunLong = getSunLongitude($nm, $timeZone); // sun longitude at local midnight
if ($sunLong >= 9) {
$nm = getNewMoonDay($k-1, $timeZone);
}
return $nm;
}
function getLeapMonthOffset($a11, $timeZone) {
$k = INT(($a11 - 2415021.076998695) / 29.530588853 + 0.5);
$last = 0;
$i = 1; // We start with the month following lunar month 11
$arc = getSunLongitude(getNewMoonDay($k + $i, $timeZone), $timeZone);
do {
$last = $arc;
$i = $i + 1;
$arc = getSunLongitude(getNewMoonDay($k + $i, $timeZone), $timeZone);
} while ($arc != $last && $i < 14);
return $i - 1;
}
/* Comvert solar date dd/mm/yyyy to the corresponding lunar date */
function convertSolar2Lunar($dd, $mm, $yy, $timeZone) {
$dayNumber = jdFromDate($dd, $mm, $yy);
$k = INT(($dayNumber - 2415021.076998695) / 29.530588853);
$monthStart = getNewMoonDay($k+1, $timeZone);
if ($monthStart > $dayNumber) {
$monthStart = getNewMoonDay($k, $timeZone);
}
$a11 = getLunarMonth11($yy, $timeZone);
$b11 = $a11;
if ($a11 >= $monthStart) {
$lunarYear = $yy;
$a11 = getLunarMonth11($yy-1, $timeZone);
} else {
$lunarYear = $yy+1;
$b11 = getLunarMonth11($yy+1, $timeZone);
}
$lunarDay = $dayNumber - $monthStart + 1;
$diff = INT(($monthStart - $a11)/29);
$lunarLeap = 0;
$lunarMonth = $diff + 11;
if ($b11 - $a11 > 365) {
$leapMonthDiff = getLeapMonthOffset($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, $lunarLeap);
}
/* Convert a lunar date to the corresponding solar date */
function convertLunar2Solar($lunarDay, $lunarMonth, $lunarYear, $lunarLeap, $timeZone) {
if ($lunarMonth < 11) {
$a11 = getLunarMonth11($lunarYear-1, $timeZone);
$b11 = getLunarMonth11($lunarYear, $timeZone);
} else {
$a11 = getLunarMonth11($lunarYear, $timeZone);
$b11 = getLunarMonth11($lunarYear+1, $timeZone);
}
$k = INT(0.5 + ($a11 - 2415021.076998695) / 29.530588853);
$off = $lunarMonth - 11;
if ($off < 0) {
$off += 12;
}
if ($b11 - $a11 > 365) {
$leapOff = getLeapMonthOffset($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;
}
}
$monthStart = getNewMoonDay($k + $off, $timeZone);
return jdToDate($monthStart + $lunarDay - 1);
}
?>
Đổi ngày dương ra ngày âm
\n";
echo "Dương lịch: $dd/$mm/$yy => ";
$s = "Âm lịch: $al[0]/$al[1]/$al[2]";
if ($al[3] == 1) $s = $s . " nhuận";
echo "$s\n";
?>