When a vault session is delayed, some backup images may be missed if the time window does not allow Vault to select images from a wider time range. For example, suppose the time window for your daily profile extends from 1 day ago to 0 days ago. On Tuesday, the robot has mechanical problems and the Vault profile fails. Consequently, Monday night's backups are not vaulted. On Wednesday, the robot is fixed. When the next Vault session begins on Wednesday, it only selects backup images that were created during the previous 24 hours, so Monday night's backups still are not vaulted. If the profile's time window had spanned more than 1 day, the session would have picked up both Monday night's and Tuesday night's backups.