What happens if you change other attributes than font-size of the .ListDate class, or add new ones, like background-color?

Are you using a custom skin / container for your portal, or one of the default DNN skins? If it's a custom skin, then perhaps (just a guess) it contains an interfering definition for .ListDate. You can check this with the Firebug add-on for Firefox - right-click on one of the list dates and check in the "Style! window where that element gets it's CSS styles gets from. Or check it with an default skin / container in a new portal.

(And, of course you know that .ListDate is used in the list view only)

I checked your site with Firebug, and it seems that your .ListDate style is overridden by a default span style. That's the code of the first entry of the "This Week at Andy's" module:

<td class="ListDate">
    <span id="dnn_ctr367_Events_EventList_lstEvents_ctl02_lblEventBegin">4/3/2008 5:00 PM</span>
</td>

In your /Portals/_default/Skins/andys/skin.css, there's this style definition in line 36:

div, span, p, td, th, li, input, textarea
{
    ....
    font-size:12px;
    ....
}

So the font size definition for the inner span overrides the definition for the outer td. Try the following:

td.ListDate span
{
     font-size: 7pt;
}

If THAT doesn't help, make it

    font-size: 7pt !important;

That definitely did the trick.  I need to get some more practice with that Firebug tool.  Thanks for the assistance, I missed that style in the skin style sheet.

Thanks!