Email Alert Not Received After Setting Alert Schedule Time

Hi

I have setup an alert that emails me when a device is down.  The alert works correctly.  I have now edited the alert and have added a schedule to only trigger alerts between 9am - 5pm.

The issue I have is that if a device goes down at 7 am I do not get an e-mail even if the device is down for a day.

If there a way to make the alert trigger at 9am?

Thanks