diff --git a/tools/checkin_check.py b/tools/checkin_check.py
index 1f1bcd4..55fef1f 100644
--- a/tools/checkin_check.py
+++ b/tools/checkin_check.py
@@ -66,7 +66,7 @@ USAGE:
   python3 checkin_check.py --repo /root/troupe-standup
   python3 checkin_check.py --repo . --gaps --json /tmp/checkins.json
   python3 checkin_check.py --dir /tmp/fake/checkins --roster volt,zephyrus --today 2026-10-18
-  python3 checkin_check.py --selftest          # 26 cells, names, dates, roster, refusals
+  python3 checkin_check.py --selftest          # 27 cells, names, dates, roster, refusals
 """
 from __future__ import annotations
 
@@ -277,7 +277,13 @@ def gaps(rows, today: date, cap: int = 60):
                     longest, run_end = run, cur
             cur += timedelta(days=1)
         since = (today - last).days
-        out.append({"handle": h, "files": len(by_handle[h]),
+        # `days` and `files` are different numbers: zephyrus has 44 files across
+        # 23 days, and a table that called the second one "files" would be the
+        # exact defect this archive keeps grading other people for.
+        nfiles = sum(1 for r in rows
+                     if r["handle"] == h
+                     and not ("BAD_DATE" in r["class"] or "FUTURE" in r["class"]))
+        out.append({"handle": h, "files": nfiles, "days": len(by_handle[h]),
                     "first": days[0], "last": days[-1],
                     "days_in_span": (last - first).days + 1,
                     "missing": missing[:cap], "missing_count": len(missing),
@@ -396,11 +402,11 @@ def print_report(rep, show_gaps: bool, fail: bool):
           f"files lack a Did/Blocked/Next/Ask heading")
     print(f"  -- A1: the four-heading rule postdates the archive; grade it where it applies")
     if show_gaps:
-        print(f"\n{'handle':<12} {'files':>5} {'first':>10} {'last':>10} "
+        print(f"\n{'handle':<12} {'files':>5} {'days':>5} {'first':>10} {'last':>10} "
               f"{'span':>4} {'miss':>4} {'gap':>4} {'idle':>4}")
         for g in rep["gaps"]:
-            print(f"{g['handle']:<12} {g['files']:>5} {g['first']:>10} {g['last']:>10} "
-                  f"{g['days_in_span']:>4} {g['missing_count']:>4} "
+            print(f"{g['handle']:<12} {g['files']:>5} {g['days']:>5} {g['first']:>10} "
+                  f"{g['last']:>10} {g['days_in_span']:>4} {g['missing_count']:>4} "
                   f"{g['longest_gap']:>4} {g['days_since_last']:>4}")
         print("  -- A2: a missing day is not a repo fault; it is a decision an operator owes")
 
@@ -521,6 +527,9 @@ def selftest():
         cell("c19 the gap axis counts missing days inside a handle's span",
              g["volt"]["missing_count"] == 1 and g["volt"]["longest_gap"] == 1,
              str(g.get("volt")))
+        cell("c27 'files' and 'days' are two columns, not one",
+             g["zephyrus"]["files"] == 2 and g["zephyrus"]["days"] == 1,
+             str(g.get("zephyrus")))
 
         rc_fail = print_report(rep, True, True)
         cell("c20 --fail exits 1 when a fault exists", rc_fail == 1, str(rc_fail))
@@ -549,7 +558,7 @@ def selftest():
         cell("c26 a malformed --since refuses at rc 2, never 1",
              main(["--dir", ck, "--roster", "volt", "--since", "16-10-2026"]) == 2)
 
-    print(f"selftest: 26 cells, {26 - len(bad)} passed, {len(bad)} failed")
+    print(f"selftest: 27 cells, {27 - len(bad)} passed, {len(bad)} failed")
     return 1 if bad else 0