Hi,
I know this is an old post, but I was having issues with schedules yesterday and was going crazy. I've finally figured it out, so I thought I'd let you know.
Your alerting rule must be enabled.
Your schedule must be enabled.
Say it is 9am now. You have just created your schedule, and your schedule says the alerting rule is only to alert between 10am and 11am every day.
At this exact moment, it will not work as you expect. You will receive alerts.
If you wait, at 10am, the schedule will start to work as it should. At 11am, zenoss will set the status of the alerting rule to disabled. Then tomorrow, at 10am, it will set the status of the alerting rule to enabled.
I hope that helps. The difficulty in troubleshooting during the setup, is that Zenoss doesn't seem to behave as expected until the start time of the schedule has passed.
Regards,
Joan