A bare 6ch is a border-box width in Gloss, and the input token padding
alone eats ~5ch of it — the spinner took the rest and left no room to
click or see a caret.

Assisted-by: GLM-5.3 via pi

diff --git a/public/admin.css b/public/admin.css
index daa2ab0..12db45b 100644
--- a/public/admin.css
+++ b/public/admin.css
@@ -119,8 +119,12 @@
    and the line it reads on matches the prose the details page
    renders (Birthday#to_s's "December 10, 1985"). The month select
    grows to carry "September"; the number inputs hold their own
-   widths and shed the same block padding every other record control
-   sheds. */
+   widths, which are the digits and spinner they must show plus the
+   box's own chrome — border-box widths count the padding and border
+   inside, so a bare 6ch left ~1ch of content and nothing to click a
+   caret into. Derived from the padding var so the pair moves with
+   the token; the same block-padding shed every other record control
+   gets. */
 .card-body form.field-stack .field > .date-row {
   display: flex;
   gap: var(--gl-space-2xs);
@@ -131,7 +135,7 @@
 }
 .card-body form.field-stack .field > .date-row > input {
   flex: 0 0 auto;
-  width: 6ch;
+  width: calc(7ch + 2 * var(--gl-space-s) + 2px);
   padding-block: var(--gl-space-2xs);
 }
 /* A multiline control has no single line to align a caption to, and