Snippet to create date formats in Drupal.

date-formats.php

<?php
  // Array of type => format.
  $formats = array(
    'day_monthname_year' => 'j \d\e F \d\e Y',
    'weekday_day_monthname_year' => 'l j \d\e F \d\e Y',
  );
  
  $query_types = db_insert('date_format_type')->fields(array('type', 'title'));
  $query_formats = db_insert('date_formats')->fields(array('format', 'type'));
  foreach ($formats as $type => $format) {
    $query_types->values(array(
      'type' => $type,
      'title' => $type,
    ));
    $query_formats->values(array(
      'format' => $format,
      'type' => 'custom',
    ));
    variable_set('date_format_' . $type, $format);
  }
  $query_types->execute();
  $query_formats->execute();