Drupal: theme_date_display_range with a human friendly date.

gistfile1.php

//
//implements theme_date_display_range()
//A more human friendly date range
//Example output:
//Oct 8 to 15, 2015
//Oct 8 to Nov 3, 2015
//Oct 8, 2015 to Jan 3, 2016
function dnv_date_display_range($variables) {
  $timezone = $variables['timezone'];
  $attributes_start = $variables['attributes_start'];
  $attributes_end = $variables['attributes_end'];
  $start_time = strtotime($variables['dates']['value']['formatted_iso']);
  $end_time = strtotime($variables['dates']['value2']['formatted_iso']);

  //Different year
  if ((date('Y', $start_time) != date('Y', $end_time))) {
    $date1 = date('M j, Y', $start_time);
    $date2 = date('M j, Y', $end_time);
  }
  //Different Month of the same year
  elseif ((date('F', $start_time) != date('F', $end_time))) {
    $date1 = date('M j', $start_time);
    $date2 = date('M j, Y', $end_time);
  }
  //Different day in the month
  else {
    $date1 = date('M j', $start_time);
    $date2 = date('j, Y', $end_time);
  }

  $start_date = '<span class="date-display-start"' . drupal_attributes($attributes_start) . '>' . $date1 . '</span>';
  $end_date = '<span class="date-display-end"' . drupal_attributes($attributes_end) . '>' . $date2 . $timezone . '</span>';

  // If microdata attributes for the start date property have been passed in,
  // add the microdata in meta tags.
  if (!empty($variables['add_microdata'])) {
    $start_date .= '<meta' . drupal_attributes($variables['microdata']['value']['#attributes']) . '/>';
    $end_date .= '<meta' . drupal_attributes($variables['microdata']['value2']['#attributes']) . '/>';
  }

  // Wrap the result with the attributes.
  return t('!start-date to !end-date', array(
    '!start-date' => $start_date,
    '!end-date' => $end_date,
  ));
}