--- HTML-CalendarMonthSimple-1.24/CalendarMonthSimple.pm.orig	2004-11-21 00:31:04.000000000 +0100
+++ HTML-CalendarMonthSimple-1.24/CalendarMonthSimple.pm	2004-11-21 00:31:55.000000000 +0100
@@ -269,7 +269,7 @@
          }
 
          # Get the cell's coloration and CSS class
-         if ($self->year == $todayyear && $self->month == $todaymonth && $thisday == $todaydate)
+         if ($self->year == $todayyear && $self->month == $todaymonth && defined $thisday && $thisday == $todaydate)
                                               { $thisbgcolor = $self->datecolor($thisday) || $todaycolor;
                                                 $thisbordercolor = $self->datebordercolor($thisday) || $todaybordercolor;
                                                 $thiscontentcolor = $self->datecontentcolor($thisday) || $todaycontentcolor;