You can configure Symantec endpoint scan frequency to match your needs. For example: if you run a backup job during the night and the Symantec endpoint scan can stop the process – you can just "tell" the Symantec  endpoint to stop scanning in the night when the backup takes place.
Follow this procedure:

1. Open the Symantec endpoint protection client.
2. Go to > change settings.
3. Press "configure settings" under "Proactive threat protection".
4. Under "scan frequency" tab, press the "at a custom scanning frequency" and fill in the time you want.