change class demo script

change class demo script

I have a script (thanks to brian.jquery12) which changes the class on my body, which changes the bgrd colour of my page. This imitates the changes seen during the day in the real sky.

I would now like a script which speeds up the whole process for demo purposes when a button/link is clicked.

The class change occurs at the following times of day 0, 7, 12, 15 & 18.

I am not sure where to start with this. Any tips or links to other posts. I have searched but not found what I need.

The page I am working on can be seen at www.superbo.fr/

Cheers

Dave