+Keep the last <N> backups.
+
+`--keep-monthly` `<N>` ::
+
+Keep backups for the last <N> different months. If there is morethan one backup for a single month, only the latest one is kept.
+
+`--keep-weekly` `<N>` ::
+
+Keep backups for the last <N> different weeks. If there is morethan one backup for a single week, only the latest one is kept.
+
+`--keep-yearly` `<N>` ::
+
+Keep backups for the last <N> different years. If there is morethan one backup for a single year, only the latest one is kept.