Is sitefinity modifying JS dates on the client?

...like the object, not literally changing a date value.

Here's why I ask:
- Take my kendo JsFiddler demo here: jsfiddle.net/.../
- So you can see that in the render function there's a "data" object which has a value property.  So inspecting it in firebug shows that data object having other properties related to the calendar object.
- So if I take this code and move it into sitefinity I get DIFFERENT results.  That data object is no longer an object, but just a date value with a SF method (and a couple others) attached.

Which causes me issues because I can't then get at the css\linkcss\value props of the "data" object.

Steve