There are many other datepickers available on the Internet...this happens to be the one that I wrote. You are free to use it in your own applications. I've attached the MIT license to this code, which should work in most situations.
The format of the datepicker (color, fonts, etc.) is easily customized using CSS. The date format can be customized using either global variables or each time you call the function that displays the date picker (see the code for more information). Enjoy.