Past dates in calendar

It would be nice to have an option to style past events differently in the calendar widget.

I tried this patch: (Line 1684)

        for ($semaine = 0; $semaine <= 5; $semaine++) {   // 6 semaines par mois
            $ret.='<tr>';
            for ($journee = 0; $journee <= 6; $journee++) { // 7 jours par semaine
                if ($NoJour > 0 && $NoJour <= $JourMax) { // si le jour est valide a afficher
                    $td = '<td class="event_post_day">';
                    if ($sqldate . '-' . ($NoJour<10?'0':'').$NoJour == $cejour) {
                        $td = '<td class="event_post_day_now">';
                    }
                    
                    if ($sqldate . '-' . ($NoJour<10?'0':'').$NoJour < $cejour)
                      $td = '<td class="event_post_day_over">'; // Patch ahf

                    $ret.=$td;

                    $ret.= $this->display_caldate(mktime(0, 0, 0, $mois, $NoJour, $annee), $cat, false, $colored, $thumbnail);
                    $ret.='</td>';
                } else {
                    $ret.='<td></td>';
                }
                $NoJour ++;
            }
            $ret.='</tr>';
        }

Seems to work.