DanCoulter

Once activated, this plugin will translate every instance of the jQuery UI 
Datepicker plugin on your blog. It even comes with the latest version of 
the jQuery plugin, so that you can add it to pages on your blog.
This will only work with version of the Datepicker plugin that come with 
jQuery UI versions 1.5 or higher.

Datepicker i18n

Globally translate your jQuery UI Datepicker instances.

CodingFabian

Because WPML creates posts and pages for each language, comments from one do not appear on the other. 
This plugin merges comments from all WPML translations of the posts and pages, so that they all are displayed on each other. 
Comments are internally still attached to the post or page they were made on.
It uses the <code>get_comments()</code> api call, which in some circumstances might not return all posts.

WPML comment merging

This plugin merges comments from all WPML translations of the posts and pages, so that they all are displayed on each other.

Datepicker i18n vs WPML comment merging