Backups via WHM - setting the schedule specifically?

We have backups running via WHM to a FTP server - where I see we can set daily, weekly, monthly - but can we specify what time during the day the backups are being done so it won't interfere with other heavy server load tasks?

Looking at the emails I get when the backup is complete, it seems like it's doing it at all sorts of random times.

Also - is there a way to change the priority at which the backup is being run?

From stackoverflow

• Although cPanel does not provide any direct control over that, I believe you should be able to change the day at which the backups are performed by changing /wsbackup/cpbackup/monthly's time stamp. cPanel will execute the backup when the directory is older than 29 days.

  I am working to figure out how to specify an actual day.

  Josh