code a script

I have domains where I want to send their web traffic to several different domain parking firms on a regular schedule each 24 hour time period. For example, the domains are all registered at same registrar and each parking firm where I have accounts uses two nameservers i.e. [login to view URL] [login to view URL] or [login to view URL] [login to view URL] etc for as many as 5 (or less) parking firms using as many as 5 sets of name servers. I will set the number of minutes between rotation from an easy to use admin menu where as many as 5 nameservers can be set or edited and the rotation schedule set, for example as short as 20-minutes per nameserver set to as long as 180 minutes rotation schedule and everything in between. So for example, every 20-min or as many as 180-min the namesevers will automatically change to as many as 5 firms changing the rotation on the admin selected interval.