Helping a friend with website where he provides fire department promotional instruction. He asked me about putting a calendar of some sorts or something similar so that when people sign up for his classes they can pick which day they want to attend and sign up for that day but he wants it to show in real time the people signed up for his class. As first he asked me about embedding a google calendar on there but I dont see how that would work. Anyone ever see anything like this online?

You can use a date picker and fire an ajax request or do a page refresh to show how many have signed up based on a database.

The date picker option sounds interesting but greek to me LOL