ui-clearfix on datepicker header with nearby floats causes vertical stretch

There's no way to modify the clearfix helper class (and have it be effective) to prevent this and it's not reasonable to not have the clearfix helper class on the datepicker and its header (things get much worse even just in this case without them).

For comparison, note that the following image does not show that there's a bug in the h2:

[[Image(https://pzt.me/dx/img/7/e/x/7exw.png)]]

It simply shows that part of the element's contents can fit in the float and part of it cannot. This is what's happening with the datepicker due to it and its header needing clearfix.

Use the position:absolute workaround you found, or add float:left to your #test div or its container.