circadian_css_animation.php

<style type="text/css">
	@keyframes color-animation {
    ...
<?php
  foreach($sun as $k => $v){
    $momentSeconds = $v - $zeroSecondTs;
    $dayPercent = (int)($momentSeconds / 864);
?>
    /* The color during <?= $k; ?> */
      <?= $dayPercent ?>% {
         background: <?= $bgColors[$k] ?>;
         color: <?= $textColors[$k] ?>;
      }
<?php
  }//end foreach sun cycle data point
?>