From 9d27366b3ec42eccf96ccc323dab13579426d7f5 Mon Sep 17 00:00:00 2001
From: quanticsoul4772 <71096528+quanticsoul4772@users.noreply.github.com>
Date: Thu, 29 Oct 2026 07:06:57 -0700
Subject: [PATCH 1/4] fix(fires): show a 47.6-hour-old detection as 2d, not 48h

formatAge and formatAgeLabel picked the hour unit on the raw value and
rounded afterwards, so a detection between 47.5 and 48 hours old read
48h, while one exactly 48 hours old read 2d. Round to whole hours first,
then choose the unit.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 docs/CURRENT-STATE.md           |  1 +
 src/layers/firms/model.js       |  8 +++++---
 src/layers/firms/model.test.mjs | 24 ++++++++++++++++++++++++
 3 files changed, 30 insertions(+), 3 deletions(-)
 create mode 100644 src/layers/firms/model.test.mjs

diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index 87b918a4e..71aa36964 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -2221,6 +2221,7 @@ accessible name remains "Don't show this again". Control behavior is unchanged.
 ## FIRMS source status
 
 The FIRMS CSV parser rejects impossible acquisition calendar dates before the proxy filters records to the trailing 24 hours, while retaining valid UTC acquisition times.
+FIRMS ages round to whole hours before choosing a unit, so a 47.6-hour age reads "2d", not "48h".
 The `get_active_fires` tool reports acquisition times as UTC ISO timestamps,
 including zero-padded hours and minutes; missing or invalid dates and times
 remain `null`, including impossible calendar dates from a custom source.
diff --git a/src/layers/firms/model.js b/src/layers/firms/model.js
index 9e3cf7f95..7dcf255c8 100644
--- a/src/layers/firms/model.js
+++ b/src/layers/firms/model.js
@@ -526,7 +526,8 @@ export function createModel({
     if (!Number.isFinite(deltaMs) || deltaMs < 0) return '';
     const hours = deltaMs / 3600000;
     if (hours < 1) return '<1h';
-    if (hours < 48) return `${Math.round(hours)}h`;
+    const wholeHours = Math.round(hours);
+    if (wholeHours < 48) return `${wholeHours}h`;
     return `${Math.round(hours / 24)}d`;
   }
 
@@ -561,8 +562,9 @@ export function createModel({
     if (!Number.isFinite(deltaMs) || deltaMs < 0) return '';
     const hours = deltaMs / 3600000;
     if (hours < 1) return t('<1h', { context: 'age' });
-    if (hours < 48)
-      return t('{count}h', { context: 'age', count: Math.round(hours) });
+    const wholeHours = Math.round(hours);
+    if (wholeHours < 48)
+      return t('{count}h', { context: 'age', count: wholeHours });
     return t('{count}d', { context: 'age', count: Math.round(hours / 24) });
   }
 
diff --git a/src/layers/firms/model.test.mjs b/src/layers/firms/model.test.mjs
new file mode 100644
index 000000000..7ff12cf3f
--- /dev/null
+++ b/src/layers/firms/model.test.mjs
@@ -0,0 +1,24 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { getLocale, setLocale } from '../../i18n/index.js';
+import { createModel } from './model.js';
+
+const HOUR_MS = 3600000;
+
+test('a fire age that rounds to 48 hours reads in days, as 48 hours does', () => {
+  const previousLocale = getLocale();
+  const { formatAge, formatAgeLabel } = createModel({
+    services: { anchors: {} },
+  });
+  try {
+    setLocale('en');
+    assert.equal(formatAge(47.4 * HOUR_MS), '47h');
+    assert.equal(formatAge(47.6 * HOUR_MS), '2d');
+    assert.equal(formatAge(48 * HOUR_MS), '2d');
+    assert.equal(formatAgeLabel(47.4 * HOUR_MS), '47h');
+    assert.equal(formatAgeLabel(47.6 * HOUR_MS), formatAgeLabel(48 * HOUR_MS));
+    assert.equal(formatAgeLabel(48 * HOUR_MS), '2d');
+  } finally {
+    setLocale(previousLocale);
+  }
+});

From a4bd028bd2626d71d7c237f8bc675b36de5c3f3f Mon Sep 17 00:00:00 2001
From: quanticsoul4772 <71096528+quanticsoul4772@users.noreply.github.com>
Date: Tue, 3 Nov 2026 11:47:41 -0800
Subject: [PATCH 2/4] changelog: FIRMS age rounding (#1531)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 changelog.d/1531-firms-age-rounding.md | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 changelog.d/1531-firms-age-rounding.md

diff --git a/changelog.d/1531-firms-age-rounding.md b/changelog.d/1531-firms-age-rounding.md
new file mode 100644
index 000000000..e8cc12c4b
--- /dev/null
+++ b/changelog.d/1531-firms-age-rounding.md
@@ -0,0 +1,3 @@
+- FIRMS fire ages round to whole hours before choosing a unit, so a detection
+  47.5–48 hours old reads "2d", as one exactly 48 hours old does, not "48h"
+  (@quanticsoul4772, #1531).

From ceff3eb6c97e7995938488417a66ed3e1b5af0ac Mon Sep 17 00:00:00 2001
From: quanticsoul4772 <71096528+quanticsoul4772@users.noreply.github.com>
Date: Thu, 5 Nov 2026 05:43:40 -0800
Subject: [PATCH 3/4] test(fires): pin the 47.5-hour flip to days and name
 where the age shows

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 changelog.d/1531-firms-age-rounding.md | 8 +++++---
 docs/CURRENT-STATE.md                  | 2 +-
 src/layers/firms/model.test.mjs        | 2 ++
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/changelog.d/1531-firms-age-rounding.md b/changelog.d/1531-firms-age-rounding.md
index e8cc12c4b..cd9bcfc5d 100644
--- a/changelog.d/1531-firms-age-rounding.md
+++ b/changelog.d/1531-firms-age-rounding.md
@@ -1,3 +1,5 @@
-- FIRMS fire ages round to whole hours before choosing a unit, so a detection
-  47.5–48 hours old reads "2d", as one exactly 48 hours old does, not "48h"
-  (@quanticsoul4772, #1531).
+- FIRMS fire ages round to whole hours before choosing a unit, so an age of
+  47.5–48 hours reads "2d", as exactly 48 hours does, not "48h". Detections
+  are filtered to the trailing 24 hours, so this shows mostly in the
+  `STALE · cached {age}` stats line after about two days without a successful
+  refresh (@quanticsoul4772, #1531).
diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index 726201138..1e1230833 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -2382,7 +2382,7 @@ reporting are unchanged.
 ## FIRMS source status
 
 The FIRMS CSV parser rejects impossible acquisition calendar dates before the proxy filters records to the trailing 24 hours, while retaining valid UTC acquisition times.
-FIRMS ages round to whole hours before choosing a unit, so a 47.6-hour age reads "2d", not "48h".
+FIRMS ages round to whole hours before choosing a unit, so a 47.6-hour age reads "2d", not "48h"; with detections filtered to 24 hours, this shows mostly in the `STALE · cached {age}` stats line.
 The `get_active_fires` tool reports acquisition times as UTC ISO timestamps,
 including zero-padded hours and minutes; missing or invalid dates and times
 remain `null`, including impossible calendar dates from a custom source.
diff --git a/src/layers/firms/model.test.mjs b/src/layers/firms/model.test.mjs
index 7ff12cf3f..a0df2eb2c 100644
--- a/src/layers/firms/model.test.mjs
+++ b/src/layers/firms/model.test.mjs
@@ -13,9 +13,11 @@ test('a fire age that rounds to 48 hours reads in days, as 48 hours does', () =>
   try {
     setLocale('en');
     assert.equal(formatAge(47.4 * HOUR_MS), '47h');
+    assert.equal(formatAge(47.5 * HOUR_MS), '2d');
     assert.equal(formatAge(47.6 * HOUR_MS), '2d');
     assert.equal(formatAge(48 * HOUR_MS), '2d');
     assert.equal(formatAgeLabel(47.4 * HOUR_MS), '47h');
+    assert.equal(formatAgeLabel(47.5 * HOUR_MS), '2d');
     assert.equal(formatAgeLabel(47.6 * HOUR_MS), formatAgeLabel(48 * HOUR_MS));
     assert.equal(formatAgeLabel(48 * HOUR_MS), '2d');
   } finally {

From fc6944951b4bb53d64965a0d1930779b4e57e45b Mon Sep 17 00:00:00 2001
From: quanticsoul4772 <71096528+quanticsoul4772@users.noreply.github.com>
Date: Mon, 9 Nov 2026 05:35:23 -0800
Subject: [PATCH 4/4] refactor(fires): read both age formatters' unit from one
 helper

formatAge and formatAgeLabel repeated the validity guard, the <1h case,
the rounding and the 48-hour switch, which is why the rounding fix had to
land twice. Both now read { unit, count } from a private ageParts, so
they cannot pick different units again. Output is unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/layers/firms/model.js       | 36 +++++++++++++++++++++------------
 src/layers/firms/model.test.mjs | 19 +++++++++++++++++
 2 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/src/layers/firms/model.js b/src/layers/firms/model.js
index 4f12593f2..00873c2b2 100644
--- a/src/layers/firms/model.js
+++ b/src/layers/firms/model.js
@@ -535,15 +535,26 @@ export function createModel({
     return `${isolate(latPart)} ${isolate(lonPart)}`;
   }
 
+  /**
+   * Millisecond delta → `{ unit: '<1h' | 'h' | 'd', count }`, or null for
+   * invalid input. Both age formatters read it, so they pick the same unit.
+   */
+
+  function ageParts(deltaMs) {
+    if (!Number.isFinite(deltaMs) || deltaMs < 0) return null;
+    const hours = deltaMs / 3600000;
+    if (hours < 1) return { unit: '<1h', count: 0 };
+    const wholeHours = Math.round(hours);
+    if (wholeHours < 48) return { unit: 'h', count: wholeHours };
+    return { unit: 'd', count: Math.round(hours / 24) };
+  }
+
   /** Millisecond delta → "<1h" / "Xh" / "Xd", or '' for invalid input. */
 
   function formatAge(deltaMs) {
-    if (!Number.isFinite(deltaMs) || deltaMs < 0) return '';
-    const hours = deltaMs / 3600000;
-    if (hours < 1) return '<1h';
-    const wholeHours = Math.round(hours);
-    if (wholeHours < 48) return `${wholeHours}h`;
-    return `${Math.round(hours / 24)}d`;
+    const age = ageParts(deltaMs);
+    if (!age) return '';
+    return age.unit === '<1h' ? '<1h' : `${age.count}${age.unit}`;
   }
 
   /** Millisecond delta → "<1m ago" / "Xm ago" / "Xh ago" (fresh-feed readout). */
@@ -574,13 +585,12 @@ export function createModel({
   /** formatAge for a card: "<1h", "24h", "3d" in the UI language ("24 ч"). */
 
   function formatAgeLabel(deltaMs) {
-    if (!Number.isFinite(deltaMs) || deltaMs < 0) return '';
-    const hours = deltaMs / 3600000;
-    if (hours < 1) return t('<1h', { context: 'age' });
-    const wholeHours = Math.round(hours);
-    if (wholeHours < 48)
-      return t('{count}h', { context: 'age', count: wholeHours });
-    return t('{count}d', { context: 'age', count: Math.round(hours / 24) });
+    const age = ageParts(deltaMs);
+    if (!age) return '';
+    if (age.unit === '<1h') return t('<1h', { context: 'age' });
+    return age.unit === 'h'
+      ? t('{count}h', { context: 'age', count: age.count })
+      : t('{count}d', { context: 'age', count: age.count });
   }
 
   /** Normalized 0..1 confidence → low/nominal/high display bucket. */
diff --git a/src/layers/firms/model.test.mjs b/src/layers/firms/model.test.mjs
index a0df2eb2c..2c42227f8 100644
--- a/src/layers/firms/model.test.mjs
+++ b/src/layers/firms/model.test.mjs
@@ -24,3 +24,22 @@ test('a fire age that rounds to 48 hours reads in days, as 48 hours does', () =>
     setLocale(previousLocale);
   }
 });
+
+test('both fire age formatters agree on invalid, sub-hour and multi-day ages', () => {
+  const previousLocale = getLocale();
+  const { formatAge, formatAgeLabel } = createModel({
+    services: { anchors: {} },
+  });
+  try {
+    setLocale('en');
+    for (const format of [formatAge, formatAgeLabel]) {
+      assert.equal(format(-1), '');
+      assert.equal(format(Number.NaN), '');
+      assert.equal(format(0.5 * HOUR_MS), '<1h');
+      assert.equal(format(1 * HOUR_MS), '1h');
+      assert.equal(format(72 * HOUR_MS), '3d');
+    }
+  } finally {
+    setLocale(previousLocale);
+  }
+});