Moon phase ++

<?php
/*
Based on the JavaScript
Lunar Phase Calculator
by Stephen R. Schmitt
which was adapted from a BASIC program from the Astronomical Computing column of Sky & Telescope, April 1994
*/

function isdayofmonth($month, $day, $year)
{
    $dim = array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
    if ($month != 2)
    {
        if (1 <= $day && $day <= $dim[$month - 1])
            return true;
        else
            return false;
    }
    $feb = $dim[1];
    if (isleapyear($year))
    {
        $feb++;// is leap year
    }

    if (1 <= $day && $day <= $feb)
    {
        return true;
    }
    return false;
}

function isleapyear($year)
{
    $a = floor($year - 4 * floor($year / 4));
    $b = floor($year - 100 * floor($year / 100));
    $c = floor($year - 400 * floor($year / 400));

    // possible leap year

    if ($a == 0)
    {
        if ($b == 0 && $c != 0)
            return false;// not leap year
        else
            return true;// is leap year
    }
    return false;
}

// compute moon position and phase
function moon_posit($month = null, $day = null, $year = null)
{
    $moon = array();
    if(!isdayofmonth($month, $day, $year))
    {
        $moon['errors'] = 'Invalid date';
    }
    else
    {
        $moon['errors'] = null;
        $age = 0.0;// Moon's age in days from New Moon
        $distance = 0.0;// Moon's distance in Earth radii
        $latitude = 0.0;// Moon's ecliptic latitude in degrees
        $longitude = 0.0;// Moon's ecliptic longitude in degrees
        $phase = '';
        $zodiac = '';
        $YY = 0;
        $MM = 0;
        $K1 = 0;
        $K2 = 0;
        $K3 = 0;
        $JD = 0;
        $IP = 0.0;
        $DP = 0.0;
        $NP = 0.0;
        $RP = 0.0;

        // calculate the Julian date at 12h UT

        $YY = $year - floor((12 - $month) / 10);
        $MM = $month + 9;
        if ($MM >= 12)
        {
            $MM = $MM - 12;
        }
        $K1 = floor(365.25 * ($YY + 4712));
        $K2 = floor(30.6 * $MM + 0.5);
        $K3 = floor(floor(($YY / 100) + 49) * 0.75) - 38;
        $JD = $K1 + $K2 + $day + 59;// for dates in Julian calendar
        if ($JD > 2299160)
        {
            $JD = $JD - $K3;// for Gregorian calendar
        }

        // calculate moon's age in days

        $IP = normalize(($JD - 2451550.1) / 29.530588853);
        $age = $IP * 29.53;
        if ($age <  1.84566)
            $phase = 'NEW';
        else if ($age <  5.53699)
            $phase = 'Evening crescent';
        else if ($age <  9.22831)
            $phase = 'First quarter';
        else if ($age < 12.91963)
            $phase = 'Waxing gibbous';
        else if ($age < 16.61096)
            $phase = 'FULL';
        else if ($age < 20.30228)
            $phase = 'Waning gibbous';
        else if ($age < 23.99361)
            $phase = 'Last quarter';
        else if ($age < 27.68493)
            $phase = 'Morning crescent';
        else
            $phase = 'NEW';

        $IP = $IP * 2 * pi();// Convert phase to radians

        // calculate moon's distance

        $DP = 2 * pi() * normalize(($JD - 2451562.2) / 27.55454988);
        $distance = 60.4 - 3.3 * cos($DP) - 0.6 * cos(2 * $IP - $DP) - 0.5 * cos(2 * $IP);

        // calculate moon's ecliptic latitude

        $NP = 2 * pi() * normalize(($JD - 2451565.2) / 27.212220817);
        $latitude = 5.1 * sin($NP);

        // calculate moon's ecliptic longitude

        $RP = normalize(($JD - 2451555.8) / 27.321582241);
        $longitude = 360 * $RP + 6.3 * sin($DP) + 1.3 * sin(2 * $IP - $DP) + 0.7 * sin(2 * $IP);
        if ($longitude <  33.18)
            $zodiac = 'Pisces';
        else if ($longitude <  51.16)
            $zodiac = 'Aries';
        else if ($longitude <  93.44)
            $zodiac = 'Taurus';
        else if ($longitude < 119.48)
            $zodiac = 'Gemini';
        else if ($longitude < 135.30)
            $zodiac = 'Cancer';
        else if ($longitude < 173.34)
            $zodiac = 'Leo';
        else if ($longitude < 224.17)
            $zodiac = 'Virgo';
        else if ($longitude < 242.57)
            $zodiac = 'Libra';
        else if ($longitude < 271.26)
            $zodiac = 'Scorpio';
        else if ($longitude < 302.49)
            $zodiac = 'Sagittarius';
        else if ($longitude < 311.72)
            $zodiac = 'Capricorn';
        else if ($longitude < 348.58)
            $zodiac = 'Aquarius';
        else
            $zodiac = 'Pisces';

        // so longitude is not greater than 360!

        if ($longitude > 360)
            $longitude = $longitude - 360;
        $moon['age'] = round($age, 2);
        $moon['distance'] = round($distance, 2);
        $moon['latitude'] = round($latitude, 2);
        $moon['longitude'] = round($longitude, 2);
        $moon['phase'] = $phase;
        $moon['zodiac'] = $zodiac;
    }
    return $moon;
}

// normalize values to range 0...1

function normalize($v)
{
    $v = $v - floor($v);
    if ($v < 0)
    {
        $v++;
    }
    return $v;
}
?>

<?php

include('moon2.php');

$date = time();
$year = date('Y', $date);
$month = date('n', $date);
$day = date('j', $date);
$moon = moon_posit($month, $day, $year);

//debug results

echo '<pre>';
print_r($moon);
echo '</pre>';

if ($moon['errors'] === null)
{
    //output and format what you want
}
else
{
    //handle error how you want, perhaps give error message and then show today''s moon info
}
?>