Community Calendars
Community calendars can provide a useful service in compiling important community dates. Here are a couple of examples of community calendars. In the first example, you have a clickable calendar, tabular presentation of events, and the possibility of searching for events by date, category, or keyword. It can also be formatted for easy printing.
By hovering your mouse over an event in the second example, the box opens with the what/where/when details of the event. You can click to get additional details. http://sjc.utah.gov/calendar/calendar.asp
Keep in mind that calendars are, by definition, time sensitive. They will require frequent updating. Even in systems where individuals and organizations are able to enter their own events for posting, there will still be some work required. It usually takes frequent reminders and lots of encouragement to get communities used to posting events.