I think it should exclude the current week. That is what I would most expect just from the language. Although it is ambiguous, and you could logically be referring to the "last of the weeks that have backups", I would more expect "the last week" to be different from "the current week". If it surprises someone one way or the other, the more unfortunate surprise would probably be if it didn't keep quite as many as expected. For example, someone who chooses to keep snapshots of the last 1 day, the last 1 week, and the last 1 month, and then finds out when they need to recover something that they only have the single most recent backup of less than a day ago, might feel misled. I think it would be safer to err on the side of retention. I would favor replacing "last N" with "preceding N" or "previous N" to be clear about it and then making sure that the behavior matches that. - Derek