Provided the file has a consistent name you could use the file existence component monitor and schedule this application to only be managed during a specified time using the Unmanage Scheduling Utility.
The Unmanage Scheduler? If you don't already have this, it's a freebie additional component that you can download from your customer portal. The download link is in the Orion NPM section, but it's compatible with APM 3.5 and later.
See Customer Portal > Additional Components > Download Orion NPM Components > Unmanage Scheduler
Keep in mind the File Existence monitor only fails if the file is missing. It doesn't compare dates. So if yesterday's file is still there when 8:30am the next day rolls around, it'll say "Yup, the file is there" and not fail.
What you might want to do instead is create a File Age monitor. Create one that fails if the file is older than 24 hours, and then put that on an 8:30am-9:00am managed cycle.
If the file is finds at 8:30am is older than 24 hours, it'll fail. If the file isn't there, it will also fail.
The Unmanage Scheduling Utility has been included as part of the default APM installation since v4.0.1. On the Orion APM server it's located under [Start - Programs - SolarWinds Orion - Advanced Features]
