FlipClockJS - Multiple Instances + data-countdown

Trying to make flipclock.js work in multiple instances while taking data from "data-countdown"

HTML

<script src="https://rawgit.com/objectivehtml/FlipClock/master/compiled/flipclock.min.js"></script>
<div class="clock-1" data-countdown="2015/07/15 17:12:20" style="margin:2em;"></div>
<div class="message"></div>
<div class="clock-1" data-countdown="2015/07/15 23:19:35" style="margin:2em;"></div>
<div class="message"></div>
<div class="clock-1" data-countdown="2015/07/15 19:18:27" style="margin:2em;"></div>
<div class="message"></div>
<div class="clock-1" data-countdown="2015/07/15 16:47:40" style="margin:2em;"></div>
<div class="message"></div>
<div class="clock-1" data-countdown="2015/07/15 22:12:44" style="margin:2em;"></div>
<div class="message"></div>

CSS

/* Get the bourbon mixin from http://bourbon.io */
/* Reset */
.flip-clock-wrapper * {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    -ms-box-sizing: border-box;
    -o-box-sizing: border-box;
    box-sizing: border-box;
    -webkit-backface-visibility: hidden;
    -moz-backface-visibility: hidden;
    -ms-backface-visibility: hidden;
    -o-backface-visibility: hidden;
    backface-visibility: hidden;
}

.flip-clock-wrapper a {
  cursor: pointer;
  text-decoration: none;
  color: #ccc; }

.flip-clock-wrapper a:hover {
  color: #fff; }

.flip-clock-wrapper ul {
  list-style: none; }

.flip-clock-wrapper.clearfix:before,
.flip-clock-wrapper.clearfix:after {
  content: " ";
  display: table; }

.flip-clock-wrapper.clearfix:after {
  clear: both; }

.flip-clock-wrapper.clearfix {
  *zoom: 1; }

/* Main */
.flip-clock-wrapper {
  font: normal 11px "Helvetica Neue", Helvetica, sans-serif;
  -webkit-user-select: none; }

.flip-clock-meridium {
  background: none !important;
  box-shadow: 0 0 0 !important;
  font-size: 36px !important; }

.flip-clock-meridium a { color: #313333; }

.flip-clock-wrapper {
  text-align: center;
  position: relative;
  width: 100%;
  margin: 1em;
}

.flip-clock-wrapper:before,
.flip-clock-wrapper:after {
    content: " "; /* 1 */
    display: table; /* 2 */
}
.flip-clock-wrapper:after {
    clear: both;
}

/* Skeleton */
.flip-clock-wrapper ul {
  position: relative;
  float: left;
  margin: 5px;
  width: 60px;
  height: 90px;
  font-size: 80px;
  font-weight: bold;
  line-height: 87px;
  border-radius: 6px;
  background: #000;
}

.flip-clock-wrapper ul li {
  z-index: 1;
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  line-height: 87px;
  text-decoration: none !important;
}

.flip-clock-wrapper ul li:first-child {
  z-index: 2; }

.flip-clock-wrapper ul li a {
  display: block;
  height: 100%;
  -webkit-perspective: 200px;
  -moz-perspective: 200px;
  perspective: 200px;
  margin: 0...

JavaScript

var clocks = [];                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             ...