show calendar based on more than one field

I want my calendare to be based on date from multiple fields in my form. Another words I want it to be based on more than one field. How can i do this? I'm thinking it is in "view definitions and has to do with the following:

options
    (
        show calendar based on Seminar_Date1
    )

Of course when i add more fields into the function i get errors. This is what im doing...

options
    (
        show calendar based on Seminar_Date1
        show calendar based on Seminar_Date2
        show calendar based on Seminar_Date3
        show calendar based on Seminar_Date4
    )

Secondly is there a way to have a singe entry show ore information right on the calendar with out needing to click on an event.

My scenario is as follows, company signs up to a seminar on a specific date. They have some number of people attending. I want to see the company atending as well as how many attendees right form the calendar view.
Is this possible?

Thanks for the help