The month name translations for Spanish had been missing. Please update your file ./languages/SMW_LanguageEs.php to revision 48832 or later to obtain the month names.

I do not know how the template achieves the "X de Y de Z" format. This result might be based on some presupposed date structure that may also have changed in the new SMW version (in particular, SMW no longer uses the MW formatting functions due to their limited range). Maximum control over the appearance of dates can be achieved by using "ISO" output (done by changing the printout to "?Date of something#ISO"), and then using ParserFunctions to decompose and process the standardised date string in the template. This is of course slower than the built-in format.