Good webmasters are always looking for ways to make visitors feel more comfortable with their sites. They are also receptive to adding anything which causes their visitors to come back time and again, as long as it fits with their theme and works well with the site.
One way to get people to come back to your site is to add things that they can use from day-to-day. This way, they will want to visit your site to, at the very least, perform the function that you've provided.
Some calendars allow your visitors to create their own events, and the more complex ones even allow them to create their own password protected calendars. The simpler versions are configurable by the webmaster, and are mostly useful for showing events which pertain to the web site. Each of these different types can find good use on just about any web site.
Some good calendaring systems include the following.
A simple, webmaster configurable calendar is useful for showing events for the web site or group. For example, the webmaster might schedule chats, conference calls or other events, and use a calendar to show his visitors when these things occur. In this case, nothing fancy is needed since the only purpose is to communicate information to the visitors.
You can also use one of the above services (and there are many others available) to define calendars which your visitors can tailor and manipulate. Generally these allow your visitors to define their own calendars for their own purposes. This type of calendar is typical for making a site more sticky, since it provides an additional reason for people to return.
Personally, I prefer using scripted calendaring solutions directly on my own web site. This allows me to have complete control over all functions of the calendar, including format and functions. Generally, I will virtually always prefer a local solution than a remotely hosted solution, all other things being equal.
The cgi-resources.com site contains a couple of dozen different scripted solutions for calendaring. This is a great place to start your search for a product to do what you need.
There is not much else to say about including calendars on a web site. They are a simple and effective way to communicate important dates to your visitors. You can also provide configurable versions to add stickiness to your site.
Unless otherwise noted, all photos and text is Copyright © Richard G Lowe, Jr.