The ability to schedule polling on a per device basis is non-existent and on alerts is very crude. Many financial firms have servcies that shut down briefly after US markets close and before overseas markets open. I am told to simply disable the alerts during those periods. It is a waste of resources to poll devices you know will be down simply to have the alerter ignore the polls. Additionally, to set up an alert that does not poll M-F 4:30-445 takes about two alerters and then add Sunday-well, you see where this all leads to!
Your competitors (I am a consultant and work with many products) have solved this problem with a simple day and time grid. Even World of Warcraft Parental Controls has this!
Thanks.