No one in their right mind likes pop-up windows and personally, the thought of embedding JavaScript blocks within the (X)HTML just doesn’t do it for Brian, so, Brian coded an Unobtrusive Date-Picker that was accessible using the keyboard and suitable for use within documents served as application/xhtml+xml (as no document.write statements are used). The date-picker attempts to auto-detect the language of the users browser installation and download the corresponding language file from the server. And also, it has the nice fade in and fade out effect.

Requirements: Modern Browsers with Javascript Enabled
Demo: http://www.frequency-decoder.com/demo/fd-date-picker/
License: Creative Commons License