PHP Analog clock

<?php
$height = 450;
$width = 450;
$img = imagecreatetruecolor($width, $height);

$black = imagecolorallocate($img, 0, 0, 0);
$white = imagecolorallocate($img, 255, 255, 255);
$red   = imagecolorallocate($img, 255, 0, 0);
$gray  = imagecolorallocate($img, 105, 105, 105);

imagefill($img, 0, 0, $black);

$dx = $width / 2; // Zeropoint x
$dy = $height / 2; // Zeropoint y
$hr = 100; // Hour radius
$mr = 120; // Minute radius

$hour = date("G", time() + 3600);
$min = intval(date("i", time() + 3600));

$hdeg = 90 - 0.5 * ($hour * 60 + $min); // Hour degrees
$mdeg = 90 - 6.0001 * ($hour * 60 + $min); // Minute degrees

$hx = cos(deg2rad($hdeg)) * $hr; // Hour x-pos
$hy = sin(deg2rad($hdeg)) * $hr; // Hour y-pos

$mx = cos(deg2rad($mdeg)) * $mr; // Minute x-pos
$my = sin(deg2rad($mdeg)) * $mr; // Minuty y-pos

imagesetthickness($img, 5);
imageline($img, $dx, $dy, $dx + $hx, $dy - $hy, $white); // Draw hour line
imagesetthickness($img, 2);
imageline($img, $dx, $dy, $dx + $mx, $dy - $my, $white); // Draw minute line
imagesetthickness($img, 1);

for($i = 0; $i < 60; $i++) { // Every minute (5th degree)
  $ld = 90 - 6.0001 * $i;
  $lx = cos(deg2rad($ld));
  $ly = sin(deg2rad($ld));

  imageline($img, $dx + $lx * 140, //x1
                  $dy - $ly * 140, //y1
                  $dx + $lx * 150, //x2
                  $dy - $ly * 150, //y2
                  $gray);

  if($i % 5 == 0) { // Every hour
  imagesetthickness($img, 3);
  imageline($img, $dx + $lx * 130, //x1
                  $dy - $ly * 130, //y1
                  $dx + $lx * 150, //x2
                  $dy - $ly * 150, //y2
                  $red);
  imagesetthickness($img, 1);

  $x = ($dx + $lx * 165);
  $y = ($dy - $ly * 165);

  imagestring($img, 3, $x - 3, $y - 5, preg_replace("/^0$/", "12", $i / 5), $gray);
  }

}

imageellipse($img, $dx, $dy, 300, 300, $white);

imagestring($img, 5, $width / 2 - 20, 20, "Kello", $white);
imagestring($img, 5, $width / 2 - 20, 35, date("H:i", time() + 3600), $white);

header("Content-type: image/png");
imagepng($img);
?>