diff --git a/docs/misc/prune-example-interval.txt b/docs/misc/prune-example-interval.txt
index f318e4f42..0106a69f2 100644
--- a/docs/misc/prune-example-interval.txt
+++ b/docs/misc/prune-example-interval.txt
@@ -7,9 +7,9 @@ to "thin out" over time while retaining most recent archives. Your backup
 script runs `borg create`, immediately followed by `borg prune`.
 
 Assume today is 2026-06-04 and you always start your backups at 16:00. You have
-been creating backup archives starting at 16:00 on most days going back to late
-2025. Today, `borg create` took a little longer than usual. It's 16:12 now and
-you run `borg prune`.
+been creating backup archives starting at 16:00, followed by pruning, on most
+days going back to late 2025. Today, `borg create` took a little longer than
+usual. It's 16:12 now and you run `borg prune`.
 
 You want Borg to keep one archive per day for one week, four weekly archives,
 one archive per month for five months, and two yearly backups. For that, you
@@ -115,16 +115,22 @@ later reference time, e.g. `--since '2026-06-04 23:59:59'`.
 and `--keep-monthly`, too. The archive is effectively kept by `--keep-daily`,
 but how this affects other rules differs between *count*- and *interval*-based
 policies. For *interval*-based rules like `--keep-monthly 5m` it has no effect:
-The rule simply keeps one archive fewer.
+The rule simply keeps one archive fewer in that case.
 
 For *count*-based rules like `--keep-weekly 4` it has an effect: The policy
-tells Borg to keep 4 weekly archives, and if 2026-05-31 is kept by another
-rule already, Borg compensates by keeping an older archive instead.
-Consequently, Borg will also keep the 2026-05-03 archive.
+tells Borg to keep 4 weekly archives. Weekly slots are identified by ISO week
+number; in this example the four kept archives cover weeks 18 through 21. If
+2026-05-31 is kept by another rule already, Borg compensates by keeping an
+older archive instead. Consequently, Borg will also keep the 2026-05-03 archive.
 
-Since 2026-05-24 and 2026-03-31 were skipped, there are no perfect candidates
-for that week and month. Borg chooses the next best candidate, so it keeps
-2026-05-23 as the weekly and 2026-03-30 as the monthly candidate.
+The week 22 slot is consumed by that same 2026-05-31 archive. Any other
+archive from that week is not kept by weekly, even if it falls within the
+daily window boundary. This is why 2026-05-27 is pruned: it has just fallen
+out of the daily window, and no other rule covers it.
+
+Since 2026-05-24 and 2026-03-31 were skipped, Borg substitutes the next best
+candidate for each: 2026-05-23 fills the week 21 weekly slot, and 2026-03-30
+fills the March monthly slot.
 
 The implementation of `--keep-monthly 5m` is somewhat special: Borg defines a
 month as a fixed 31-day period, independent of the actual calendar dates
@@ -144,6 +150,6 @@ Intervals and counts can be mixed freely. Yearly retention in this example is
 done by retention count instead of intervals. A count rule paired with interval
 rules behaves just as it would if all preceding rules were also counts:
 Archives already kept by earlier rules are excluded from consideration. In this
-example there is only one "true" yearly candidate, so the oldest archive at
-2025-11-15 is kept. This oldest archive will be kept until the rolling backup
-scheme reaches "steady state" (when all retention rules are fully satisfied).
+example, every yearly slot is consumed by earlier rules; no true yearly
+candidate remains, so the oldest archive at 2025-11-15 is kept to preserve
+rolling backup semantics.
diff --git a/src/borg/testsuite/archiver/prune_cmd_test.py b/src/borg/testsuite/archiver/prune_cmd_test.py
index 23c12029d..6b1617f73 100644
--- a/src/borg/testsuite/archiver/prune_cmd_test.py
+++ b/src/borg/testsuite/archiver/prune_cmd_test.py
@@ -123,9 +123,7 @@ def test_prune_repository_example_interval(archivers, request, backup_files):
 
     # All timestamps are at exactly 16:00 UTC (matching the example).
     # Backups on most days from 2025-11-15 to 2026-06-04, with skips on
-    # 2026-03-31 and 2026-06-03. At the inclusive interval boundaries,
-    # 2026-05-28 (1w before --since) and 2025-12-31 (155d before --since)
-    # are kept.
+    # 2026-03-31, 2026-05-24, and 2026-06-03.
     archive_dates = [
         (2025, 11, 15),
         (2025, 12, 31),
@@ -133,6 +131,11 @@ def test_prune_repository_example_interval(archivers, request, backup_files):
         (2026, 2, 28),
         (2026, 3, 30),
         (2026, 4, 30),
+        (2026, 5, 3),
+        (2026, 5, 10),
+        (2026, 5, 17),
+        (2026, 5, 23),
+        (2026, 5, 27),
         (2026, 5, 28),
         (2026, 5, 29),
         (2026, 5, 30),
@@ -153,6 +156,7 @@ def test_prune_repository_example_interval(archivers, request, backup_files):
         "--dry-run",
         "--since=2026-06-04T16:00:00+00:00",
         "--keep-daily=1w",
+        "--keep-weekly=4",
         "--keep-monthly=5m",
         "--keep-yearly=2",
     )
@@ -166,18 +170,27 @@ def test_prune_repository_example_interval(archivers, request, backup_files):
         "backup_2026-05-31",
         "backup_2026-05-30",
         "backup_2026-05-29",
-        # 2026-05-28 is at the inclusive boundary (exactly 1w before --since).
         "backup_2026-05-28",
     ]
     for i, name in enumerate(daily_kept, 1):
         assert re.search(rf"Keeping archive \(rule: daily #{i}\):\s+{name}", output)
 
+    # Weekly W22 slot is consumed by 05-31 (already kept by daily),
+    # so weekly reaches back to W18 to fill all 4 slots.
+    weekly_kept = [
+        "backup_2026-05-23",  # W21 — no Sunday candidate (05-24 skipped)
+        "backup_2026-05-17",  # W20
+        "backup_2026-05-10",  # W19
+        "backup_2026-05-03",  # W18
+    ]
+    for i, name in enumerate(weekly_kept, 1):
+        assert re.search(rf"Keeping archive \(rule: weekly #{i}\):\s+{name}", output)
+
     monthly_kept = [
         "backup_2026-04-30",
         "backup_2026-03-30",
         "backup_2026-02-28",
         "backup_2026-01-31",
-        # 2025-12-31 is at the inclusive boundary (exactly 155d before --since).
         "backup_2025-12-31",
     ]
     for i, name in enumerate(monthly_kept, 1):
@@ -186,6 +199,11 @@ def test_prune_repository_example_interval(archivers, request, backup_files):
     # No true yearly candidates remain; only the oldest archive fills the slot.
     assert re.search(r"Keeping archive \(rule: yearly\[oldest\] #1\):\s+backup_2025-11-15", output)
 
+    # 05-27 was kept by daily yesterday (window started 05-26) but falls out
+    # today (window shifted to 05-28). W22 slot is consumed by daily-held 05-31,
+    # so weekly doesn't save it either.
+    assert re.search(r"Would prune:\s+backup_2026-05-27", output)
+
 
 def test_prune_quarterly(archivers, request, backup_files):
     # Example worked through by hand when developing the quarterly