Q:

Alternative method for using Microdata datetime in HTML5 for HTML4

This code is for HTML5:
<time itemprop="datePublished" datetime="2012-01-07T07:07:21+00:00">January 7, 2012</time>

Can I use this code for HTML4? 
<div itemprop="datePublished">
    <span dateCreated="2012-01-07T07:07:21+00:00">January 7, 2012</span>
</div>

Or something like this? 

A:

Note that Microdata is specified for HTML5, not for HTML 4.01 (related question).  If you don’t care about that:
HTML 4.01 doesn’t define a dateCreated attribute for the span element.  There is also no time or data element defined.  Some would misuse the abbr element, but I wouldn’t recommend that.  So you’d probably have to use a span element, and, ugly, hide the machine-readable date for your visitors. 
<span><span itemprop="datePublished" class="hidden">2012-01-07T07:07:21+00:00</span> January 7, 2012</span>

But better don’t use Microdata in HTML 4.01 documents in the first place.  You could use RDFa instead (you can also use the Schema.org vocabulary in RDFa).