hovering on a link

[Kaly]

I, am trying to find out an easy way to add a hovering message on a link. I have searched here but do not understand the directions that I found on one message. Can anyone tell me how to add it to a link. I have a calendar on the website and there is one message for 4 days that I would like for people to be able to hover on and see without having to click on the link and open a page if they didn't want to. Thanks in advance.
Kaly

[Collectors-info]

It would be far easer to use a calendar with this facility already built in. (Similar to the ones on this site)