gistfile1.phtml

<div class="<?php print $classes; ?>"<?php print $attributes; ?>>                                                                                            
  <?php if (!$label_hidden): ?>
    <div class="field-label"<?php print $title_attributes; ?>><?php print $label ?>:&nbsp;</div>                                                             
  <?php endif; ?>
  <div class="altered field-items"<?php print $content_attributes; ?>>                                                                                       
   <?php dpm($items); ?>                                                                                                                                     
      <? 
      list($start, $end)             = explode(' to ', $items[0]['#markup']);                                                                                
      list($start_date, $start_time) = explode(' ', $start);                                                                                                 
      list($end_date, $end_time)     = explode(' ', $end);                                                                                                   
      
      $start = strtotime($start);
      echo format_date($start, 'custom', 'human_time');                                                                                                      
                                                                                                                                                             
      
      ?>
      <div class="date-time-wrapper date">
         <span class="date-time date from"><?= $start_date; ?></span> 
         <?php if ($end_date && $start_date != $end_date) { ?> <span class="separator"> - </span><span class="date-time date to"><?= $end_date; ?></span> <?php } ?>
      </div>                                                                                                                                                 
                                                                                                                                                             
      <div class="date-time-wrapper time">                                                                                                                   
         <span class="date-time time from"><?= $start_time; ?></span>                                                                                        
         <?php if ($end_time) { ?><span class="separator"> - </span><span class="date-time time to"><?= $end_time; ?></span> <?php } ?>                      
      </div>                                                                                                                                                 
  </div>                                                                                                                                                     
</div>