Gosh, this seems almost canonical but... have you looked at CPAN?

There's a supergroovy module called HTML::CalendarMonth that you'd probably enjoy using. It's got gobs of functionality and it's never given me a problem for the two times I've used it.

There are some basic examples located here : http://mojotoad.com/sisk/projects/HTML-CalendarMonth/examples.html.
Note that these are more or less basic examples. There's a lot of goodness that comes with the package.

 use HTML::CalendarMonth;
 use HTML::AsSubs;


 # Using HTML::AsSubs
 $c = HTML::CalendarMonth->new( month => 3, year => 69 );
 $c->item($c->year, $c->month)->attr(bgcolor => 'wheat');
 $c->item($c->year, $c->month)->wrap_content(font({size => '+2'}));
 $c->item(12, 16, 28)->wrap_content(strong());
 print $c->as_HTML;
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