Which datepicker does EveryBlock utilize?

I've found a great datepicker on EveryBlock's web site:

http://ui-patterns.com/userset/553/image/2955开发者_运维问答#focus

Does anybody know which control do they use and is it available as a standalone control?

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Seems like a custom-made one, from looking at the JavaScript source. There is a function Calendar(a, b) with a lot of code, and something called CustomFilter. They are building their stuff on top of jQuery, though.