the database will store the date using the format Y-m-d h:m:s
to enter and display the date in a differant formation, you will need to edit the code on the page.
for example, on the update page, the code for a date picker element will be:
<input id="ProductEndDate" name="ProductEndDate" type="text" value="<?php echo((isset($_GET["invalid"])?ValidatedField("productsupdate","ProductEndDate"):"".(($row_WADAProducts["ProductEndDate"])?date("m/d/Y",strtotime($row_WADAProducts["ProductEndDate"])):"")."")); ?>" class="formTextfield_Medium" tabindex="11" onBlur="hideServerError('ProductEndDate_ServerError');">
this portion of the code:
date("m/d/Y",strtotime($row_WADAProducts["ProductEndDate"]))
displays the date using m/d/Y as the format. to change the format to dd.mm.yyyy the code would be:
date("d.m.Y",strtotime($row_WADAProducts["ProductEndDate"]))
to change the format used by the date picker element, select it in design view, and click the edit button in the property inspector, you can edit the format used in the date picker settings.