Google "html calendar". There are tons of html calendar builders, lots of which are even free. Some are online - you enter events into a grid, and some are packages you download. They all define the look-and-feel to some degree.
I would also search "event calendar" and see how others have implemented their calendars.
I have developed several, from using a basic table list of dates to using JS and CSS to display fancy ones. I usually wind up doing the work manually though. It's not much more work than using a package - you still have to type in all the event data anyway, and I get them to look the way I want.
Mike Krausnick
Dublin, California