Modify your profile, enable Expert mode (via burger menu), go to When -> Periodically, tick the "Run this profile every" checkbox and select how frequently you'd like the profile to run, e. g. every 12 hours. Note that if you see some red text saying "Background backups are currently disabled", click on the red text to enable background backups.

With V10 (and newer versions), you can configure the profile to run on the specified days and times using the options "Only run the profile on these days" and "Only run the profile between these times" (e.g. Monday to Friday from 9:00 AM to 10:00 PM).