Hi Bev,
Let me explain to you how the scheduled backup feature works with WordPress wp-cron functionality.
The backup time is set at the time you save the automatic scheduled backup settings. In order for the backup to trigger around the time you expect it to, you will need some kind of site activity (such as someone visiting) just after that time.
For example: I’ve configured my scheduled backup settings to do a once daily backup. I saved the config now and it is currently 7:11pm at my location. Then the wp-cron job will be scheduled to perform a backup at around 7:11pm everyday. What this means is that the next backup will be scheduled for tomorrow at approximately 7:11pm. However, if nobody visits my site till 10:30pm tomorrow, then no backup will occur at 7:11pm because there was no activity on the site just after 7:11pm to trigger the wp-cron event. What will happen is that the system will immediately trigger a backup as soon as someone visits my site anytime after the scheduled time. (In other words in this example the backup will occur at 10:30pm)
On the next day the same thing applies. The aiowps backup is still scheduled for around 7:11pm and if I get my next visitor at 7:12pm then the backup will be performed at 7:12pm.
Let me know if the above makes sense to you.
Regards