Add a monthly datepicker with jQuery - separate script
This script adds a month-year picker to a text field, and works better than a modification of jQuery datepicker.
<?php
drupal_add_js(drupal_get_path('module', 'jquery_ui') .'/jquery.ui/ui/jquery.mtz.monthpicker.js');
$sub_script = "$(document).ready(function () {
$('.add-datepicker-y-m').monthpicker({
'pattern': 'mm/yyyy'
})
}); ";
drupal_add_js($script, 'inline', 'footer');
?>Source: https://github.com/lucianocosta/jquery.mtz.monthpicker