On questions, where it shows the date there is a span element with a time (assuming it's UTC format). But there is nothing inside the element and the actual date ("1 week ago" etc) is outside it. Here's a sample:
<span class="qa-q-view-when">
<span class="qa-q-view-when-data">
<span class="published">
<span class="value-title" title="2011-07-12T18:10:37+0000"></span>
1 week
</span>
</span>
<span class="qa-q-view-when-pad"> ago</span>
</span>
Also, do we really need so many HTML tags for just 3 words? Why not something like the below? EDIT: better example containing all the classes:
<span class="qa-q-view-when published">
<span class="qa-q-view-when-data value-title" title="2011-07-12T18:10:37+0000">1 week</span>
<span class="qa-q-view-when-pad"> ago</span>
</span>
Wouldn't that be better? Here you get to keep all the microformats while trimming useless HTML tags, and fixing the bug with the exact time not appearing when hovering the 'fuzzy time'.
However, I'm not 100% sure if it's possible to have the 'published' class only on the 'qa-q-view-when' tag, since that part is generated in one generic function (it seems to add published to the 'qa-q-view-when-data' tag as well).