What happens if my backup is scheduled to run on the 31st, but the month has fewer days?

ElephantDrive backups are smart and can identify when a backup is set to run on the last day of the month. If the backup is set to run on the 31st, but the month has 30 days, then the backup will start on the 30th. Similarly, in February, if the backup is set to run on the 30th, it will run on the 28th (or 29th) of February.