Let say we want to display a date based header into our articles lists, which must be shown only if the day changes from one article to the next one. This can be easily achieved by placing exactly the same code Alex wrote two days ago into our article form:

<txp:if_different>
  <!-- heading - only once per day -->
  <h3><txp:posted format="%d %B %Y" /></h3>
</txp:if_different>