Nic, it is unclear to me what exactly you are asking for. Do you mean a web-based program that allows you to post to a specified website? Or something that will allow a calendar of events to be printed?

If the former, are you looking for a website that will host listings, or do you have one and need to add the functionality? Is so, you will need to tell us what the website is running on and what languages it accepts programming in.

I have written applications before that post up-coming events/notices dynamically where the events/notices are entered by a simple web form. Is that the sort of thing you want?