1 files changed, 25 insertions, 1 deletions
diff --git a/docs/superpowers/plans/2026-08-03-post-0.1.0-usability.md b/docs/superpowers/plans/2026-08-03-post-0.1.0-usability.md
index ff6efc4..844217e 100644
--- a/docs/superpowers/plans/2026-08-03-post-0.1.0-usability.md
+++ b/docs/superpowers/plans/2026-08-03-post-0.1.0-usability.md
@@ -118,7 +118,7 @@ taking that too literally.
 | 59 | Archive and Mark all read shipped with the same icon | presentation | XS | **done** |
 | 60 | Next thread dead-ends on the last reply of an expanded thread | defect | XS | **done**; already fixed by 5487d58, see below |
 | 61 | `test_mainwindow` fails intermittently, about 1 run in 20 | testing | S | open; predates the card list, reproduced on f72dba9 |
-| 62 | No config option for the date format on a card | presentation | XS | open |
+| 62 | No config option for the date format on a card | presentation | XS | **done** 2026-08-11 |
 | 63 | No way to see sent mail, and no filter for it | workflow | S | open |
 | 64 | The Sync button carries a mailbox icon, not a refresh one | presentation | XS | **done** 2026-08-11 |
 | 65 | No full code review and optimization pass | correctness | ? | open, unspecified |
@@ -4092,6 +4092,30 @@ and `CardDelegate` passes it down.
 
 **Size: XS.** One key, one parameter, one width calculation.
 
+### Outcome (done)
+
+Built as specced: `[general] date_format`, empty by default, passed down as a
+parameter rather than read inside `CardLayout`. Three things worth recording.
+
+- **The format reaches the LAYOUT, not only the painter.** It sits on
+  `CardLayout::Input`, because `compute()` reserves the date's width from
+  `widestDateSample()`. A pattern that reached only the `drawText` call would be
+  elided into a rect sized for the system format, which is the same clipping
+  the bold-font fault produced. The test asserts both halves and was confirmed
+  by mutation: making the width ignore the format fails it.
+- **`widestDateSample()`'s static cache had to go.** It memoised one sample, so
+  whichever format arrived first would have sized every later one. It is now a
+  plain call, at the cost of one `QLocale` lookup per row, which is what
+  formatting the date itself already costs.
+- **Validating a pattern is harder than it looks, and the first test fixture
+  was wrong.** `toString()` treats nearly every letter as a field, so `banana`
+  formats as `bpmnpmnpm` (`a` is AM/PM, `n` the minute) and `hello` as `22ello`.
+  Those are nonsense but they vary with the instant, so a "does this contain a
+  field" check cannot reject them and should not pretend to. What `Config`
+  rejects is the case that actually harms: a pattern whose output is CONSTANT,
+  found by formatting two different instants and comparing. `xyz` is such a
+  pattern and is what the test uses.
+
 ## 63. No way to see sent mail, and no filter for it
 
 **Observed (user, from the notes):** "Sent mail filter".