We do ... but the form builder date type likes to work with a linear list of date parts, which get translated to a string of date parts separated by spaces.
Frankly the form builder date datatype is ummm ... lacking. It was incomplete and not working when we inherited ACS 4.2, I whacked at it until the bits that were there worked and fleshed it out a bit but it needs a lot more work.
Volunteers are welcome, of course! :)
