[Borgbackup] Issues understanding prune 'keep' rules

[Nils Blomqvist]

Settings:

keep-within   3d
keep-daily    7
keep-weekly   4
keep-monthly  6
keep-yearly   7

Excerpt of first prune (24 Okt 2020 10:09:51):

Keeping archive: backup-2020-07-29T19:17:17
Keeping archive: backup-2020-07-24T17:01:59
Keeping archive: backup-2020-07-19T08:10:21
Keeping archive: backup-2020-07-06T17:58:07
Pruning archive: backup-2020-07-05T08:12:26

Excerpt of second prune (5 Nov 2020 14:45:44):

Keeping archive: backup-2020-07-29T19:17:17
Pruning archive: backup-2020-07-24T17:01:59
Pruning archive: backup-2020-07-19T08:10:21
Pruning archive: backup-2020-07-06T17:58:07

In the first prune, the latest four archives are kept.
In the second, only the latest is kept.

I don’t understand how the pruning rules are applied.