Custom date token for Backdrop CMS event content type URL alias pattern

custom_date_tokens.info

name = Custom Date Tokens
description = Adds custom tokens for date fields.
package = Custom
version = BACKDROP_VERSION
type = module
backdrop = 1.x

custom_date_tokens.module

<?php
/**
 * @file
 * Provides custom tokens for building URL aliases using date fields.
 */
 
 /**
 * Implements hook_token_info().
 */
function custom_date_tokens_token_info() {
  $info['tokens']['node']['field-date-custom'] = array(
    'name' => t('Event Custom Date Format'),
    'description' => t('Custom date field value for events, format: Y-M-D.'),
  );
  return $info;
}

/**
 * Implements hook_tokens().
 */
function custom_date_tokens_tokens($type, $tokens, array $data = array(), array $options = array()) {
  $replacements = array();

  if ($type == 'node' && !empty($data['node'])) {
    $node = $data['node'];

    foreach ($tokens as $name => $original) {
      switch ($name) {
        case 'field-date-custom':
        
          $time = strtotime($node->field_event_date['und'][0]['value']);
          $newformat = date('Y-m-d',$time);
          $replacements[$original] = $newformat;

          break;
      }
    }
  }

  return $replacements;
}