Not really any links but what you do is the following:
This is from AOS 6.3 but I don't think it has changed much.
1. create a time-range first like below under access control -> time ranges
Once you have created and given your time-range a name, you apply it to your desired virtual AP profile.
That is basically it.
This is a DENY time-range, so you would have to configure your time range to be outside of business hours.
Page 247 opf the AOS guide goes through a scenario where you apply during work-hours time-ranges which are applied to an ACL instead of a Virtual AP.
If you want to read up on time-ranges, I invite you to visit the AOS users guide located here.
http://community.arubanetworks.com/aruba/attachments/aruba/unified-wired-wireless-access/27930/1/ArubaOS_6.3.xUG.pdf
page 247