This is a calendaring problem, solved very well by Google Calendar and other similar tools. They use the iCal format (generally). If you want to manage the ticketing side of things, I like Trac a lot, though a lot of people swear by Bugzilla, RT (this is in Perl), and Jira. The nice part about Trac and Jira is that they also provide a wiki tied into the ticketing system. To round the trifecta, I recommend phpBB for forums (though it sucks, it sucks less than everything else).

You'll notice I only mentioned one thing in Perl (and I don't like RT at all). A language only makes things possible. No-one has chosen to write a solid calendaring or forum software in Perl and I don't like the one solid ticketing system in Perl. You're welcome to shave that yak; I have better things to do, like using the available tools. (This is a pet peeve and I apologize for the ... strength ... of my comments.)